By enabling the NoDrivesInSendToMenu policy, you can hide drive-letters from the Send To menu in Windows Vista without actually hiding the drives in Windows Explorer environment.A point to note that NoDrivesInSendToMenu is not applicable for Windows XP systems.

* Click Start, type regedit.exe and press ENTER
* Navigate to the following location:
HKEY_CURRENT_USER \ Software \ Microsoft \ Windows \ CurrentVersion \
Policies \ Explorer
If the above branch does not exist by default, you'll need to create it.
* Create a new DWORD (32-bit) value named NoDrivesInSendToMenu
* Double-click NoDrivesInSendToMenu and set its value data to 1
* Exit Registry Editor. For more information please subscribe in the email.Happy computing.