Imagine to have  your personal folder in My Computer; it's a good trick that does the job; 

go to c drive (or everyelse you want) and create a new folder ( say mydir ); after made it, go to command prompt and type:

subst z: c:\mydir

now go to my computer and check it..........  there is a new z drive on it, pointing to mydir.  To remove the drive, we have to go to command prompt again,  and type:

subst z: /d

this command will remove the z drive from my computer view.