On my Eee PC running Windows Vista, I encountered the problem that Windows needs to install driver software for my USB flash drive. It happened on all USB flash drives except Toshiba Transmemory 4GB. Since I know that from Windows XP onwards, there is no need to install any additional driver to access any USB flash drive, I suspected something else.
After checking, I found that when Windows has problem identifying drivers, it stores them in C:\windows\inf\INFCACHE.1. This file can be corrupted and deleting it actually solves the problem without even rebooting. But you have edit its file permission to grant Full control to the Users group. This can be done by right clicking the file and selecting Properties.