Robin,
I uninstalled PDF creator, then renamed C:\windows\system32\spool\drivers\x64\PSCRIPT5.dll to PSCRIPT5.dll.old, tried to reinstall ran into the same problem. Did the Net stop spooler command from CMD as an admin, found 2 copies of C:\windows\system32\spool\drivers\x64\PSCRIPT5.dll including the .old one, deleted both of them. Uninstalled Pdf creator and then reinstalled again following those instructions again.
Another copy of Pscripts.dll was placed back in the folder and I ran into the same problem, at the same point during install.
Any other suggestions?