Defining Local and Remote Drive Visibility Under Windows NT 4.0 or Windows 2000

This article was previously published under Q158457
Windows NT 4.0 or Windows 2000 administrators can define drive visibility on a per-drivebasis by using the NODRIVES entry in the registry.
WARNING: Using Registry Editor incorrectly can cause serious, system-wideproblems that may require you to reinstall the operating system to correct them.

Microsoft cannot guarantee that any problems resulting from the use ofRegistry Editor can be solved. Use this tool at your own risk.

The NODRIVES entry (reg_dword) located in
<B>HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies \Explorer</B>

uses a 32-bit word to define local and network drive visibility foreach logical drive in the computer.

The lower 26 bits of the 32-bit word correspond to drive letters Athrough Z. Drives are visible when set to 0 and hidden when set to 1.Drive A is represented by the rightmost position of the bitmask whenthe radix is viewed in binary mode.
Example: A bitmask of 10000000000000000000000111(0x7h)
The bitmask above hides local drives A, B, and C (rightmost bits fromright to left) and drive Z (leftmost bit).

A bit mask of 11111111111111111111111111 (0x3FFFFFFh) would hide all driveletters.

Administrators may also use the NODRIVES entry to disable access to floppydrives on a per-user basis, replacing functionality previously found inthe Floplock.exe utility from the Windows NT 3.x resource kits.

Drives hidden using the NODRIVES setting are not available through WindowsNT Explorer, under the My Computer icon, or in the File Open\Save dialogboxes of Windows applications. File Manager and the Windows NT commandprompt are not affected by this registry setting.

NOTE: If you hide the System drive it is not available under the MyComputer icon or in the File Open\Save dialog boxes, however it is visiblein Windows NT Explorer.
4.00 prodnt floplock.exe

Article ID: 158457 - Last Review: 02/26/2007 19:38:34 - Revision: 2.2

Microsoft Windows 2000 Server, Microsoft Windows 2000 Advanced Server, Microsoft Windows 2000 Professional Edition, Microsoft Windows NT Workstation 4.0 Developer Edition, Microsoft Windows NT Server 4.0 Standard Edition

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