I originally ran into this problem trying to fix my Adobe PDF (virtual) printer, but now I receive this error message when I attempt to install every printer. I went to Control Panel and validated my copy of Windows 7. I am up to date on al the required updates.
I almost feel I have "lost" the core driver package, and I would love to just simply re-install it. But, I can't find it on my Windows 7 install disc. I can't find an MSU or Hotfix that would just reinstall my core driver package.
Unfortunately, my System Restore only went back a month. I have no idea when the ability to access the "core driver package" went away, but I've already gone back to my earliest remaining System Restore.