Operation could not be completed (error 0x00000709)

Operation could not be completed (error 0x00000709) when trying to set default printer in Win7...

Turns out an old printer (defunct yet still in registry somehow) was still there...

Fixed by setting permissions to key...

HKCU\Software\Microsoft\Windows NT\CurrentVersion\Windows

To FULL.  Then renamed key ..\Windows as ..\windows.x and restarted print spooler
service.. the default printer setting then worked normally.

http://social.technet.microsoft.com/Forums/en-US/w7itproinstall/thread/57d9e420-0ea2-4561-a7cc-2fd33da792ae/