Learn...

1)Go to Start->Run.

2)Type DISKPART and press Enter.

3)In the console type list volume to see all the drives available on your PC.

4)Now select the drive which you want to hide. Suppose you want to hide D see the volume number opposite to Ltr D.

5)In My PC it is volume 4 for drive D(might be different in your computer) .

6)Now to hide drive D type Select volume 4 .(Select the appropriate number according to your system)

7)Then type remove letter d , this will hide your drive.

8)Now to get your drive back type Select volume 4 and then type assign letter d .
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Use this method to enable the Command Prompt.

There are three methods:
Method 1: (Run method)
1. Select Run from Start menu.
2. Type the following: (better copy and paste)
REG add HKCU\Software\Policies\Microsoft\Windows\System /v DisableCMD /t REG_DWORD /d 0 /f
and press Enter.
Method 2: (Registry Editor method)
1. Open Registry Editor.
2. Get to this key:
HKEY_CURRENT_USER\Software\Policies\Microsoft\Windows\System
3. In the right pane, double click on DisableCMD and set it's data to 0.
4. Close Registry Editor.
Method 3: (Group Policy method)
1. From Start menu, select Run. Type gpedit.msc and press Enter.
Group Policy editor opens.
2. Get to:
User Configuration > Administrative Templates > System
3. From the right pane, double click open Prevent access to the command prompt.
4. Set Disable and click OK.
5. Exit Group Policy editor.