Proper way to remove an old driver from %systemroot%\system32\drivers

If you prefer a GUI method, use Microsoft's Autoruns for Windows. It requires no installation. Simply run it elevated, then navigate to the Drivers tab, clear the checkmark next to the driver you wish to disable, then reboot the computer:

Not only is this a simple way to enable/disable drivers and services (along with pretty much anything else that starts automatically in Windows), but it's very easy to undo changes if you find they have unwanted consequences or you're simply experimenting with your configuration.

By the way, the next time you disable a critical startup item and Windows will not boot, try using System Restore. It is capable of restoring the driver file you deleted as well as any Registry settings you might change (including changed made by Autoruns) in an effort to disable it.

Windows automatically creates Restore Points when certain critical actions are about to be taken (such as before installing Updates), but it's a good idea to create one manually before making changes to important startup items. And if your system fails to boot and you need to use a Restore Point, here are directions on how to do that.

Start regedit. In the left pane, navigate to:

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services

Now look for a subkey under services called dcrypt.

• If it’s not there, look for something of a similar name, like dskcrypt.

• If you still can’t find it, use regedit’s Find command to search for dcrypt.sys in a subkey under Services. The string dcrypt.sys should be in a value called ImagePath.

When you find the key, navigate to it and check that you do indeed see ImagePath: ...dcrypt.sys in the right pane. Now double-click the value called Start and change it to 4, which means Disabled.

That should do it.