After upgrading a printer driver on any Microsoft Operating system later than Windows XP and Server 2003, the old driver files are still being used.
Consider the following scenario:
You have a printer driver installed on the system. You attempt to install a newer version of the driver. Both the new driver and the old driver have the same name (i.e. “ABC Model 1000″). After you install the driver, the old driver’s files may still be used when printing, or the driver may no longer function correctly because registry entries for the driver are inconsistent.
For more information on this issue, including potential causes, workarounds, and resolutions, see: Microsoft KB Article KB2004234.