how to hide a particular drive or HDD partition

Download Tweak UI from here and install this application in your computer. When you will install it, open it and you will get a screen like this :Click on My Computer in the left hand side panel and select Drives. Now if you look at the right hand side panel you'll see your drives along with checkboxes. Uncheck the drive that you want to hide and click on Apply at the bottom and then click OK.

Now view your drive in My Computer ! Wow its hidden

How to access hidden partition : In the above image I hide my E:\ drive and whenever I want to access my E:\ drive, just open My Computer and in the address bar type E:\ and hit enter.