How can I hide drive x from users?

A. This can be done using the TWEAKUI utility from the"My Computer" tab, and just deselect the tick next to drives you wantto hide. All this does is change the registry valueHKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionPolicies
ExplorerNODRIVES which is a 32-bit word (DWORD). The lower 26 bits of the32-bit word correspond to drive letters A through Z. Drives are visible whenset to 0 and hidden when set to 1.

Drive A is represented by the rightmost position of the bitmask when viewedin binary mode.

e.g. A bitmask of 00000000000000000000010101(0x7h)

The bitmask above hides local drives A, C, and E

Drives hidden using the NODRIVES setting are not available through WindowsExplorer, under the My Computer icon, or in the File OpenSave dialog boxes of32bit Windows applications. File Manager and the Windows NT command prompt arenot affected by this registry setting.