Inside of Windows 7, you will need to use the printui.exe utility. Before proceeding, I would recommend removing your printer from the Devices and Printers area to prevent issues from removing the driver itself.

1. Open up a command prompt with Administrator privileges
2. Execute: printui /s /t2
3. Select the Drivers tab inside the Print Server Properties dialog box
4. Select the print driver you would like to remove and click Remove...
5. Check Remove driver and driver package.
6. Click OK

You can now reinstall the printer successfully by using group policy (if you have you have a print server) or manually with the installation wizards.