vCenter Upgrade 5.0 Error 25004.Setup failed ...

Error 25004. Setup failed to create the vCenter Server repository.

After some initial attempts to search the web and the vmware KB site to try and rectify the problem, I decided to start from scratch. I restored the vCenter Database (SQL 2005) from the SQL backup taken prior to attempting the upgrade and restarted the install. This time around the install completed successfully!

Note: I tried re-running the vCenter upgrade, multiple times after previous failed attempts, without restoring the original SQL database and I kept getting the same error.

The only thing I could think of as to why the initial install failed was the aborted install which did not rollback the database changes, even though it said it did successfully. I also noticed that after the "Successful?" rollback there were no longer any vCenter services running (which should have been running before I attempted the upgrade), they were all gone even after the reboot which lead me to believe that the rollback didn't complete correctly.

The solution that worked for me:

1) Backed out of the current install (Which failed and was supposed to rollback anyway)
  2) Rebooted the system
   3) Restored the vCenter Database (SQL 2005) from the SQL backup taken prior to attempting the  upgrade (Very Important and any good System Administrator should know to backup prior to any upgrade)
    4) Restarted the install.
    5) This time around the setup should complete successfully.