Add virtual drive to your p.c.

*Click Start and then Run. Now type cmd on the text field. The command prompt will appear. On the command prompt, type subst x: "C:\windows".

*The letter "x" represents the drive letter of the virtual drive you wish to create. You can choose any letter as long as it doesn't already exist on your computer. However, do not use the letters A, C, E, F, or Q because they are common drive letters and your computer may already be using these letters.

*C:\windows represents the directory that you want to place your virtual drive. You choose any directory or file on your computer.

After you have input this information in the command prompt, you can view the new drive by going to My Computer
Although you have created a new drive, it will automatically be deleted when the computer powers down. We need to make the new virtual drive permanent.
Here's how:

*First, open Notepad: Start >> Programs >> Accessories >> Notepad.

*Type subst x: "C:\Windows". Now save the Notepad document as c:\autoexec.bat.

*Hit Ctrl+R (or click Start >> Run) on your keyboard and type regedit then click OK.

*On the left pane of the Registry Editor, Click My Computer >>HKEY_LOCAL_MACHINE >> Software >> Microsoft >> Windows >>
CurrentVersion >> Run.

*Now on the right click on the right pane and click New.

*Select String Value. Type in "Autoexec" and press Enter.

*Right click Autoexec and click Modify.

*Type in c:\autoexec.bat.

*Close the Registry Editor and restart the computer.

Your virtual drive is now permanent. And you are done!