Every time you connect a new device to Windows, for example a USB drive , it stores many information details in the registry. It can be helpful remove old , unused or unwanted device drivers because Windows is searching for those hardware devices in every boot sequence. Also a best practice is about to clean everything out that you don't connect or use anymore to tidy things up. The freeware portable tool USB Oblivion can be used to delete USB Registry Keys or clear the USB Registry of USB drives and CD ROMs that have ever been connected to a PC by removing USB registry traces.
Compatible with 32 or 64 bit versions of Windows 2000, XP, 2003, Vista, Windows 7. Features include the ability to run in simulation mode (test without making any registry changes) and to save a backup of the registry in case something goes wrong. System requirements : Windows 2000, Windows XP, Windows 2003, Windows Vista, Windows 7 32/64-bit versions. License: Open Source Link : http://code.google.com/p/usboblivion/
See also the article : USB Swiss Army Tools Collection
Good tool...