How To Change Your Hard Drive Icon

1. Open "Regedit"

Start menu -> "regedit.exe"

or

Wondows key+"R" -> "regedit.exe"

2. Navigate to your hard drive

The location should be:
HKEY_CURRENT_USER\Software\Classes\Applications\Explorer.exe\Drives\{hard drive}\DefaultIcon

For example:
HKEY_CURRENT_USER\Software\Classes\Applications\Explorer.exe\Drives\C\DefaultIcon

If you don't have the subgroups then create them like this

Right click with your mouse -> New -> Key

3. Change the key value

Right click on the key -> modify

Enter the full location of your .ico (icon) file

4. Enjoy