Service Pack

[malagabob]

My computer constantly fails to install a service pack download. When I log off the internet I get the message "dont power off or shut down, installing updates 1of 1 or 2of 2.
When turning on after it has shut down I get the message "configuring service pack". Then after the process gets to 6% the message" failure configuring service pack reverting changes" The laptop then shuts itself down, starts up again and goes through the same steps taking anything up to 10 minutes plus.
Looking at the update list its just a load of fails.
I am running Microsoft 7 Home premium.