There are two tested methods to hide a Disk drive.

The first method is for people who are familiar with Windows Registry.But if you are not comfortable in manipulating Registry then it is advised to follow the second method.

First method to hide a Disk Drive:

Click on 'Start' and then click on 'Run' and then type 'regedit' in the box and click on OK.

Registry Editor will open. Now navigate to:

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\
Explorer

Now from the Menu bar of Registry Editor click on 'Edit' and then 'New' and select DWORD Value.

Now Rename the DWORD Value to 'NoDrives'.

Now Right Click on 'NoDrives' and Select 'Modify' , now Check 'Decmial' Option under Base.By Default Hexadecimal is selected and enter the Decimal value (under Value Data) of the Drive you would like to hide.

The list of decimal values of drive is given below:

Click OK once finished and then Restart your PC.

The Drive which you have hidden will not be displayed.

Summary : Hiding your Disk Drive:

1) Click Start.
2) Click Run.
3) Type 'regedit' in the Box.
4) Navigate to HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion \Policies\
5) Explorer.
6) From Registry Editor Menu Bar 'Edit' -> 'New' -> 'DWORD Value'.
7) Rename DWORD Value to 'NoDrives'.
8) Right click on NoDrives -> Modify -> Select 'Decimal' Option -> Put Decimal Value of Drive.
9) Click OK.

Second Method : This is a risk free method and will hide the drive instantly without any need to reboot.

Click on Start and then on Run and type in 'diskpart' in the box below:

A command prompt screen will appear.Now type 'list volume'.

It will look like this:

DISKPART> list volume

On Pressing ENTER you will see details about all the volumes.

Now type 'select disk 0'.

The following message will be prompted:

"Disk 0 is now the selected disk."

Now type in 'detail disk' and you will get all details about your hard disk and disk drives it contains.

Now type in select partition 3 (You may select any partition of your choice , here i want to hide Drive D:/ which is in Partition 3).

A message will be prompted:

"Partition 3 is now the selected partition."

Now type in 'detail partition'

This will show the disk drive in this partition.In my case its D :/ drive

Now to hide D:/ drive we type in 'remove letter D'

Now open 'My computer' and you will not see the drive.But don't worry the data is still intact.Now to get back the drive , type in 'assign letter D'.
and you will get D:/ drive back.

If you have hidden C:/ drive then type 'assign letter C' and so on.

Summary : Hiding Disk Drive the Easy Way.

1) Click Start.
2) Click Run.
3) Type 'diskpart' in the Box.
4) Type 'list volume'.
5) Type 'select disk 0'.
6) Type 'detail disk'.
7) Type 'select partition 3'.
8) Type 'detail partition'.
9) Type 'remove letter D' .