# General > Technical Support >  USB Removable Drive - Access Denied...

## Bobinovich

I have come across a weird problem twice now and wondered if anyone else had experienced it - if so what their solution was.

When plugging in a USB Flash Drive it is recognised by the Windows XP system but then comes up "F:/, Access Denied".  Other USB flash drives do exactly the same, yet work fine on all other XP systems, indicating it's not a problem with the drives themselves.

My guess is it's something to do with drive permissions, or a corruption in the registry.  I've uninstalled the respective devices & the related storage volumes from the Device Manager & let Windows re-detect which it does, but still with Access Denied when trying to open them.  I've even manually edited the CurrentControlSet in the registry but still the same problem.

When I experienced this the first time I backed up, wiped & reinstalled everything which worked fine, but is a bit extreme just to get certain USB devices to work.  However if I have to then I'll do it again - I was just hoping someone may have an idea.

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## Stumurf

sorry bobinovich, i have never had that trouble so cant really offer any real advice...

could it be an IRQ conflict?

Other than that i can only guess at it being a software error... i am not saying a bad install of XP is the culprit, are there any music programs that could be trying to connect and manage the usb device that is causing the conflict?

hope Blueivy can come to the rescue....   :Grin:

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## blueivy

> I have come across a weird problem twice now and wondered if anyone else had experienced it - if so what their solution was.
> 
> When plugging in a USB Flash Drive it is recognised by the Windows XP system but then comes up "F:/, Access Denied".  Other USB flash drives do exactly the same, yet work fine on all other XP systems, indicating it's not a problem with the drives themselves.
> 
> My guess is it's something to do with drive permissions, or a corruption in the registry.  I've uninstalled the respective devices & the related storage volumes from the Device Manager & let Windows re-detect which it does, but still with Access Denied when trying to open them.  I've even manually edited the CurrentControlSet in the registry but still the same problem.
> 
> When I experienced this the first time I backed up, wiped & reinstalled everything which worked fine, but is a bit extreme just to get certain USB devices to work.  However if I have to then I'll do it again - I was just hoping someone may have an idea.


I've had problems with drives before suddenly denying me access and the problem was actually down to group policy not being applied properly at logon to the network. While your computer may not be part of a domain, it could be down to the local machine policy on it. However that would generally restrict all (USB) drives all of the time and not just some of them.

Is this limited to one account or to all of the accounts on the machine? Have you tried to see what happens when you are logged on with the Administrator account and not just an account which is a member of Administrators?

Is there anything in the Event Viewer on the machine to indicate any problems?

If you open the USB icon on the system tray, check the Display Device Components box, select the device (not the volume) and click Properties is there anything in there that's unusual?

What are the drive permissions? Have you reset them and taken ownership of it?

The only other things that springs to mind are:a corrupted file system on the USB drive, however you'd then expect it to continue to do it even after wiping the machine.a corrupted registry and this would explain why it works when you wipe it.Virus / spyware restricting access for a laugh.I'm sure you've checked most of these but thought I'd throw them out there anyway!

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## blueivy

> hope Blueivy can come to the rescue....


Was that just a touch of sarcasm I hear there ....  :Wink:

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## Bobinovich

Thanks for those ideas.  I've looked over a few of them already but there's a couple of new ones for me to try out - I'll let you know how I get on  :Grin: .

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## Stumurf

> Was that just a touch of sarcasm I hear there ....


you have mighty fine hearing if you did..  :: 

no offence... just playin...  :Grin: 

BOBINOVICH...

are the USB Drives using FAT 32? If you have formated them to NTFS i have found that using the drives on a machine that didnt format them can cause such problems... not sure why i didnt remember this initially, but hope you get it sorted....

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## octane

just a couple of things 
With the device unplugged go into My Computer and see if drive F has already been assigned to something else. You may be running extra hardrives or dvd roms. Or have you got a virtual drive setup which has been given this letter.

If the drive has been backed up maybe try and format the flash drive as FAT instead of Fat32 and see if that works

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## Bobinovich

Hmmm, OK no luck so far.  After another visit it turned out that ALL removable storage (floppies, DVD/CD, USB drives, etc.) were causing the same error message.

I did some sleuthing and looked at the Microsoft Management Console (MMC) > Storage > Removable Storage security permissions but they are all set to Allow access.

I tried creating a new Administrator account but still got the same results when I logged into it.

It's not a drive formatting problem as the USB drives read fine on other PC's, the contents of the customer's own USB drive are still intact.

I'm not sure where else to look - I'm sure it must be a registry corruption problem but where to look?  Nevermind, there's not a lot on this particular PC so I'm just going to backup, wipe & reinstall from the recovery partition which, if nothing else, makes things speedy.

Thanks for your ideas anyway.

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## emb123

I'd go with registry corruption too.  Sorting such problems being akin to hunting for needles in haystacks.

Never encountered the problem myself so would need a hands on to play with, but past experience has shown that resultant errors and error message can often be caused by something unrelated (e.g. system clock/date settings!).

Does the drive itself show up in Windows Explorer and/or removable devices in the system tray ?

If the device is detected ok and shows as a removable drive plugged in via the system tray 'removable devices' icon but no drive letter is asigned then the problem is likely to be a conflict or corruption of available drive letters within the registry.

If the drive shows up in Windows Explorer and you can see the files but can do nothing with them then it's a file ownership problem in which case you need to become the owner of the files.

If the drive shows up in Windows Explorer but you can't see anything on it then its likely to be a drive letter problem/related bit of registry corruption or conflict with a virtual device driver/mapped drive.

Is your machine networked - any mapped drives ?  Could well be a clash of drive letters.  Maybe there's a residual association with a different location for the drive letter that Windows would ordinarily assign to the USB drive when it's plugged in.

Thinking about possible root causes it's going to be one of the following:

File permission/ownership problems on the flash drive itself (if the drive's file structure or device itself supports ownership)
usb devices corruption in registry
drive letter availability corruption in registry (old values, or virtual or mapped drives conflicting)
drive access permissions
file sharing
logged in user group permission problem
specific usb device driver trouble (unlikely)
something else apparently unrelated

Did come across this page on a Google search where specific registry keys are reset.  I looked at the related keys in my own registry and the range of keys addressed by the script is very broad.  Worth a try maybe, but on a machine which you were thinking of reinstalling anyway - just in case.

Do let us know if you get to the bottom of it  :Smile: 


p.s. just found this page among the Microsoft support pages that suggests the problem is due to registry corruption:
http://support.microsoft.com/kb/925196

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## Bobinovich

> Does the drive itself show up in Windows Explorer and/or removable devices in the system tray ?


Yep, the Floppy, DVD & USB drives all show up in Explorer, just get an "Access Denied" error when trying to access them.




> Is your machine networked - any mapped drives ?


Nope




> ...
> drive access permissions
> ...


Have pretty much narrowed it down to to this one, simply can't resolve it... 




> Did come across this page on a Google search where specific registry keys are reset. I looked at the related keys in my own registry and the range of keys addressed by the script is very broad. Worth a try maybe, but on a machine which you were thinking of reinstalling anyway - just in case.
> 
> Do let us know if you get to the bottom of it


Wouldn't mind the link to that Google page - I've a feeling I may come across this one again, most likely with the same customer! (no comments required). 

I finally backed up (to the D: partition - thankfully still accessible), used the Ghost restore partition, & re-set up software & settings.

Anyway, thanks for all the help. I did a fair amount of Googling but was unable to find a relevant solution - maybe one will appear before the next occurrence!

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## emb123

> Wouldn't mind the link to that Google page - I've a feeling I may come across this one again, most likely with the same customer! (no comments required). 
> 
> I finally backed up (to the D: partition - thankfully still accessible), used the Ghost restore partition, & re-set up software & settings.
> 
> Anyway, thanks for all the help. I did a fair amount of Googling but was unable to find a relevant solution - maybe one will appear before the next occurrence!


oops!  forgot to include the link....

http://www.jsifaq.com/SF/Tips/Tip.aspx?id=10825

Out if interest does this customer have a number of USB devices ? - most especially digital imaging stuff.  I've noticed certain makes of digital camera (Aiptek, Olympus, Panasonic, HP, Canon off the top of my head) can really screw up the USB detection on a PC.  Also some USB TV devices.

I expect you probably will come across it again. Either  some device driver is making a mess of the registry or some registry 'cleaner' is doing its usual stuff.

Sounds like the error you're getting is the same as when trying to access a network drive for which you have no permissions set up.  I suspect it's highly unlikely to be the problem but have you checked all the TCP/IP (& IPX/SPX if installed) settings, network/workgroup settings and file shares, and the user group settings  ?

Everything really would seem to point to a permissions problem, but permissions for logical 'ghost' drive (one that isn't correctly configured because the registry is screwed up in respect of the device drivers, i.e. some parts of the registry for the specific device read correctly so it appears to exist but others sections of the registry for the device are either missing or pointing to the wrong hardware) could lay the blame back with hardware configuration (within the registry) - i.e USB drivers section.

Intriguing problem - would love to come across it  :Smile:   (I must be a masochist!)

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## Bobinovich

Well if I come across it after your arrival in these parts I'll quite happily let you!  I've had just about enough of this particular problem so you're welcome to it LOL!

I don't think the problem lies in the USB side of the system as I was getting the same problem accessing ALL removable storage (i.e. floppy, CD and USB devices) so am inclined to think it was still drive permissions.  Just not sure how it could have affected all 3 devices simultaneously.

BTW for those interested it all started after the customer switched the base unit off at the wall by accident with the USB drive still plugged in, however it seems an awfully simple thing to cause such mayhem on all removable drives.

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## danielpl

Came across your post by way of referral from another forum since I had a similar problem with usb connection with a gps. 

I can't provide an answer to your problems other that by providing description of my problem and failed attempts:

 Recently upgraded my gps from legend to 76csx and when I first connected to my laptop using the usb connection, the Mapsource program recognized the unit and the micro sd card on which I installed some maps. Subsequent connections have not worked in that the Mapsource now only recognizes the sd card and not the gps unit and I can only download maps to sd card and no waypoints, tracks, etc. The garmin usb device has a yellow ! next to it in the device manager and any attempts to update-remove re-install the usb driver produces an invalid data error message alternating with access denied error messages depending on whether I used the wizard or the device manager. 

I have been able the to connect the gps to other computers and all other usb peripherals work. Latest mapsource, drivers, xp updates, etc.

I have tried some permissions changes in registry, but for some reason they do not stick, they are not saved.

I'm stumped!

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## emb123

Hi danielpl,

Not familiar with the device you mention (don't have the privilege of GPS unfortunately  :Frown:  ) but I understand the nature of the problem as you've described it.  It sounds like a related problem - in as much as it sounds like a problem within the registry.

I suppose you could try that script suggested above which contained the text*:

@echo off
setlocal
set key1=HKLM\SYSTEM\CurrentControlSet\Control\Class\{  4D36E980-E325-11CE-BFC1-08002BE10318}
set key2=HKLM\SYSTEM\CurrentControlSet\Control\Class\{  4D36E967-E325-11CE-BFC1-08002BE10318}
call :quiet>nul 2>&1
endlocal
goto :EOF
:quiet
REG DELETE %key1% /V UpperFilters /F
REG DELETE %key1% /V LowerFilters /F
REG DELETE %key2% /V LowerFilters /F
REG DELETE %key2% /V UpperFilters /F

WARNING:  This script was not written by me and I have never run it and it MAY cause problems - it will almost certainly affect unrelated drivers for other USB devices.  If your last resort is to wipe and re-install the PC anyway then I suppose it wouldn't hurt to try it  :Smile:  .

I would personally however be more inclined to go with the advice at the Microsoft Support Website ( http://support.microsoft.com/kb/925196 )
which advises you to do much the same, but manually.

The problem you're having appears to be related but not identical - in other words it may not fix it.

I noticed that there is a commercial application which offers a free trial (which may have crippled functionality - haven't checked) that claims to be able to show up precisely this type of problem as just one of the many wonderful and indispenable things it does....  
http://www.usbinfo20.com/ProductInfo.htm

Looks a bit like using a sledgehammer to crack a nut to me, but it's there if you fancy having a play with it.

Good luck, do let us know if you manage to crack this particular nut!

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*probably the easiest way to create and run the script would be to right click somewhere on your desktop and select 'new' -> 'Text Document'. Change the name to "usbfix.txt" or something similar (name is unimportant).
Open the document within notepad and copy and paste the text from above into the document. Save and close the document. Rename it to change the '.txt' to '.bat'.
You can just double click to run it after which you should shutdown and restart your PC. (Whilst you could run it from a command prompt, there is no advantage to doing so as all output has been redirected to NUL - i.e. nothing will be displayed).

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## danielpl

Tried the Microsoft link and the removal of the following keys
HKLM\SYSTEM\CurrentControlSet\Control\Class\{ 4D36E980-E325-11CE-BFC1-08002BE10318}
HKLM\SYSTEM\CurrentControlSet\Control\Class\{ 4D36E967-E325-11CE-BFC1-08002BE10318}

However, all I got was an error message indicating delete impossible.

Frustrating as all hell, especially since Garmin isn't responding anymore. They had been good in the past. Can't use the Christmas rush anymore at the end of January.
Boo, hoo! :Frown:

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## emb123

> Tried the Microsoft link and the removal of the following keys
> HKLM\SYSTEM\CurrentControlSet\Control\Class\{ 4D36E980-E325-11CE-BFC1-08002BE10318}
> HKLM\SYSTEM\CurrentControlSet\Control\Class\{ 4D36E967-E325-11CE-BFC1-08002BE10318}
> 
> However, all I got was an error message indicating delete impossible.
> 
> Frustrating as all hell, especially since Garmin isn't responding anymore. They had been good in the past. Can't use the Christmas rush anymore at the end of January.
> Boo, hoo!


You don't want to delete the 'class' just the specific filter keys.  I'm not surprised that it won't let you delete the class if you have any USB devices attached at the time.

Worth reading the Microsoft article again as I'm not sure you're trying to delete the right thing.

If you're definitely deleting the right thing and it's not letting you delete the filter keys then they are likely to be in use.

Although this is veering towards something which is 'risky' (- you might need to reinstall your Operating System, which as it sounds like your Registry has some corrupt information, probably wouldn't be a bad idea anyway), I'd suggest removing any (or at least as many as possible of the) USB devices you have connected to your PC (including using a PS2 mouse and PS2 keyboard if you have them available), then restarting your PC and trying again.

If it still doesn't work then try booting up in Safe mode (preferably without USB devices attached), and try deleting the keys again.

Once more I'll repeat the standard (and very necessary) warning that Microsoft give about injudicious editing of your registry.... if you get it wrong your PC may fail to boot and need to be re-installed.

In practise, this area of the Registry is not likely to cause boot failure but it could mess up the way the PC handles USB devices if you delete the wrong thing.... i.e. you could find that the keyboard and mouse don't work!
Good luck!

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## JEBriskham

I've had a similar problem using VPC on a Windows 7 host, running a virtual copy of XP. I shared a USB device on my host P.C, and mapped a network drive to it on my VPC. When trying to access the USB drive though on the VPC - access was denied.
My fix was - on my host plugged in my USB drive. Right click, properties, security. Set the security for everyone, or the P.C\user you are using to allow all (full control). May take a while to run depending on how much data you have on your device, as it updates each file. I have about 200Gb on my device and it took about 15 minutes to run through.
This fixed it for me, so may be worth a try?

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## M R

You do realise how old this thread is ?

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## dx100uk

Doh! 
 ::

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## JSukel

A long thread but it solved a big problem..  Properties - Security - Everyone - All.  Bingo!  Got all 29GB of data backup from the Geek squad that had become inaccessible before it loaded into the laptop with new (BLANK) hard drive.  Bless you for your help.

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