On rare occasions we will install a new printer, or a new driver, and Windows 7 will prompt "Driver Update Needed."
Start > Devices and Printers > right-click on the printer > See what's printing
Click Printer, as shown underlined in red above, and choose "Update Driver."
People with Windows XP should just remove the printer by right clicking and deleting it. Then just re-add from \\print and the new driver will be installed.