Recently my PC (running on Windows XP) started having problems with my USB flash drives (actually all USB flash drives as I found out later). My PC can detect them but can't use them. In the Device Manager, they were correctly listed but with an exclamation mark next to it meaning error. I tried to re-install the devices for each respective USB flash drives but encountered a 'This Hardware Cannot Be Installed' error message. I tried re-installing the Microsoft Service Pack 3 as well and no good, the problem still persist. It was really frustrating.
I then search for a solution in some of the Windows XP forums. None of them offered a workable solution until this forum. In one of the solutions posted, it suggested downloading the USBSTOR.inf file. That I followed and downloaded the file from this excellent site which offers .inf files for free download. I put the file in my 'Driver cache' folder under the windows folder.
I then fired up Device Manager, select the problematic flash drive, right-click and select 'Update driver'.
In the 'Hardware Update Wizard' pop-up box that appears, I selected 'Install from a list or specific location (Advanced)' and specified the folder where the downloaded file was located. Click Next ... et viola my woes are gone ! My pc can read my usb flash drive again !
That felt like magic...good magic.