nodrvman.exe 3
this will hide drives a: and b: (11)

nodrvman.exe 5
this will hide drives a: and c: (101)

nodrvman.exe 2730
this will hide drives b:, d:, f:, h:, j: and l: (101010101010)

nodrvman.exe 0
this will unhide all drives
 
nodrvman.exe 67108863
this will hide all available drives
 
nodrvman.exe unhideall
this will unhide all drives

nodrvman.exe hideall
this will hide all available drives

The "NoDrives Manager" uses a 32-bit word to define local and network drive visibility for each logical drive in the computer. The lower 26 bits of the 32-bit word correspond to drive letters A through Z. Drives are visible when set to 0 and hidden when set to 1.

Add these decimal numbers to hide the drive(s):

A: 1, B: 2, C: 4, D: 8, E: 16, F: 32, G: 64, H: 128, I: 256, J: 512, K: 1024, L: 2048, M: 4096, N: 8192, O: 16384, P: 32768, Q: 65536, R: 131072, S: 262144, T: 524288, U: 1048576, V: 2097152, W: 4194304, X: 8388608, Y: 16777216, Z: 33554432, ALL: 67108863

For example to hide drive A and drive D, you would add 1 (A) + 8 (D) which means the value should be set to "9".

To disable all the drives set the value to "67108863".  