Drive Calculator

As you may be aware (I’m guessing you are as you’ve made it to this page) there are two settings that can be used to hide and restrict access to drives on a Windows machine.

Whilst these can be set using GPO, by default the templates are quite restrictive on which drive letters you can affect. For that reason you can set the registry values yourself.

Details of the relevant settings can be found at: and

Those links will detail the location in GPO and also the registry path required. However, it does not calculate the value that you need to provide. The calculator below will allow you to generate the value needed (select the drive letters, then click Encode) or show you which drives are affected by a value (enter the value, then click Decode).