After running the exe to apply a cumulative update to your build, rather than using the gui based SharePoint Products and Technologies Wizard, use the SharePoint Management powershell console and call this command:
psconfig -cmd upgrade -inplace b2b -force
The upgrade process will go much faster.
PSConfig Technet reference, click or go here: http://technet.microsoft.com/en-us/library/cc263093(v=office.14).aspx
If you receive a failure message, navigate into your logs, located in:
C:\Program Files\Common Files\Microsoft Shared\Web Server Extentions\14\Logs
and search for ERR, make sure case sensitivity is in play by selecting the Match case box.
If the error mentions a specific timer ensure that that timer job is enabled in your farm. If it is ambiguously referencing “a timer”, make sure the SharePoint 2010 Timer service and 2010 Admin service are enabled and running in Windows, and then re-run the command
After you get a successfully applied message, navigate into the 14 hive (C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\14) and open the ISAPI folder.
Find the Microsoft.SharePoint.dll and examine the Details tab. The product version should display the updated build number for your update.
If you’re upgrade is failing, it could be due to some of your content databases. Open a management console and get-spcontentdatabase. Then run upgrade-spcontentdatabase “Name of Db” for each one. Check out -SkipIntegrityChecks if you need too.