Solution 1:
XP USB Drive not detected or installed fix
USB drives that did work with XP, suddenly don't - annoying isn't it?
this is a fix which involves editing the registry but is fairly straight forward.
Usb drives that are suddenly no longer detected or larger drives are not detected but smaller ones are may benefit from it.
http://support.microsoft.com/kb/925196
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Solution 2:
Problem:
Windows XP does not recognize USB Mass Storage Drives
Device is detected and listed with an exclaimation mark in Device Manager
Solution:
After spending hours on internet and reading through numerous posts, I found
following solutions which will definately work (as they worked for me):
1. Delete following file: windows\inf\infcache.1
2. Go to windows\inf folder and see if you have read/write permissions for
following files:
usbstor.inf
usbstor.pnf
If not, open security settings for above files and add your username for
read/write access.
3. Open registry editor and:
Delete following keys:
HKEY\System\CurrentControlSet\Enum\USB\ <read all keys and delete all those
saying USB Mass Storage Driver>
Add following keys:
HKEY\System\CurrentControlSet\Services\Usb
Add a new DWoRD Value and name it "DisableSelectiveSuspend". Give it value 1
4. Make sure you have USBSTOR.SYS file in your windows\system32\drivers folder
(It wasn't there in my case). Just Google using Usbstor.sys and you will find
the file to download. Save it at above location.
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Båda dessa svar hittade jag på:
http://forums.windrivers.com/showthread.php?t=79201
OBS! Glöm inte ta backup av Registret!
