If your system hangs about 2 or 3 minutes at startup, where you can't access the Start
button or the Taskbar, it may be due to one specific service (Background Intelligent
Transfer) running in the background. Microsoft put out a patch for this but it didn't
work for us. 
Here's what you do:
•Click on Start/Run, type 'msconfig', then click 'OK'.
•Go to the 'Services' tab, find the 'Background Intelligent Transfer' service.
•Disable it, apply the changes & reboot.