Usually when installing a major upgrade to SharePoint first you install the update (notably – SP1, The SharePoint Infrastructure Update, soon SP2) then to complete the install you must run the SharePoint Products and Technologies Configuration Wizard. On many occasions I have seen the Wizard get stuck on the final step and eventually error out. In almost every circumstance there is usually something going on with the Windows SharePoint Services Search. I have found the best way to mitigate this error is to simply stop the WSS Search Service, you can easily do this at the command line stsadm –o spsearch –stop.
Once the upgrade is done start the service from Central Administration and you should be all set. I hope this saves you time on your future upgrades.
