XP service pack 3 issue

Hello all,
My computer downloaded the Service Pack 3 a while ago but every time I try to install it, it locks up my computer. tried again last night after cleaning and defragging. Got approximately half way through installation, froze at Registry back-up.
I thought I had read a reccomendation on MG about downloading it from MG? Is that true? Could someone give me that link as I cannot find it. Any other suggestions?
Computer is a Dell XPS 400 with about 45.3 GB of free space.

Thanks in advance
Mike

 

Here's MG's link. Scroll down to almost the end of the page and you'll find it.
http://www.majorgeeks.com/downloads42.html
Good luck with the download.

 

OK, I redownloaded service pack 3 from Major geeks. I clicked the link that recommended updating drivers and downloaded uniblue driver updater and restarted computer.
Started installation of service pack 3 but again it seems to have frozen on "Backing up Registry". How long should it take for it to back up the registry?
Obviously there is another issue. Could this be caused by possible Malware? I did recently do the XP cleaning procedures from MG.

Any advice?
Mike