So you have installed the latest SharePoint Cumulative Update, you then run the Products and Services Wizard only for it to fail at some point…..We need to dissect the issue so we can get a successful upgrade. First things first we need to clear the current upgrade so that everything is clean, from the command prompt run
C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\14.0\Bin
stsadm -o setproperty -pn command-line-upgrade-running -pv No
iisreset

We can now try the upgrade again using the PSConfig command line tool and the Windows Application Event Log.
PSConfig.exe -cmd upgrade -inplace b2b -wait -force
We now get far more detail as the upgrade runs through.Sometimes this is all that is required for a successful upgrade as there may have been some transient issue during the upgrade process.However if we get nothing useful from the event log (ie database mirroring issues, etc) and receive a further failure it is time to search the upgrade log for [ERROR] or [WARNING]. This search will turn up the errors that you need to rectify.Some common errors are based on the following:

  • Solutions that have not been fully deployed or revoked
  • Content/Service Application Databases defined in the configuration but not attached

Once we have resolved any issues we can run through the steps specified above to attempt to finalised the upgrade once more.