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