1. type GPEDIT.MSC in the run box and press enter
2. then click on ADMINISTRATIVE TEMPLATES under USER CONFIGURATION on the left pane.
3. then on the right pane double click on WINDOWS COMPONENTS.
4. then again on the right pane double click on WINDOWS EXPLORER.
5. then you will get a lot of options where u can find HIDE THESE SPECIFIED DRIVES IN MY COMPUTER.
6. double click on it and u can specify which drive u want to hide.