As always, the first thing to do is to reinstall the application. You can do this using the REPAIR button when you uninstall it or use the setup package you have to perform a fresh installation.
Secondly, reinstall the printer(s). You can either remove the driver manually using Device Manager or use Uninstall a Program in Control Panel to remove its contents.
Once the driver is removed, unplug the printer and the reinstall it using its setup CD or installation package.