There are few ways for hiding your drive in your computer but the one very simple in window 7 is discussed below in steps.
1. Right click on computer icon and click on Manage as shown in below picture.
2. A computer management window will popup and you will find the "Disk Manager" on your left panel just click on it.
3. In the lower panel you will see all the partitioned drives you have in your computer. Right click on any drive you want to hide and click on "Change drive letter & paths for E: (Data)".
4. Another small window will open where you can see the drive name in a box and a few buttons as shown.
5. For hiding the drive click on Remove button while drive name is selected. By clicking the remove button a warning window will appear on it title bar Disk Management will be written. Click you Yes button and your drive will hide. Go to My computer and you will see there will be no E drive.
6. For showing again the drive in your computer just go through the steps from 1 to 4 but in step for this time you have to click on "Add" button instead of Remove button, select the letter for your drive and click yes and you will see the drive again in your computer.
Benefits:
Every one have personnel data on their drive and no one wants to his personnel data to be leaked out. So you need to hide your personnel drives so that it can not be seen to the one who uses your system without letting your know. This tutorial help protect your personnel data.