Hide entire hard drives c: or d: or f: without regedit

1. Go to Start > run > type "diskpart".
A DOS window will appear with following discription.
DISKPART>

2. Then type "list volume"

The result will look like : ------

Volume ### Ltr Label Fs Type Size Status Info
--------------- --- -------- ---- ------ ---- ------ ----
Volume 0 F CD-ROM
Volume 1 C Window_XP NTFS Partition 7000MB Healthy System
Volume 2 D Softwares NTFS Partition 8000MB Healthy
Volume 3 E Songs NTFS Partition 8000MB Healthy

3. Suppose u wanna hide drive E then type "select volume 3"

Then a message will appear in same winwods { Volume 3 is the selected volume}

4. Now type "remove letter E"
Now a message will come { Diskpart Removed the Drive letter }
sometime it requires the reboot the computer .

Diskpart will remove the letter .Windows XP is not having capabilty to identify the unkown volume.

Your Data is safe now from all unauthorised users.
To access the content of hidden Drive repeat the process mentioned above. But in 4th step replace " remove" to "assign"
i mean type "assign letter E"

source: here