mudbox driving me crazy!

"an uknown error has occurred..."
i work 5 mins and then crash..

i got sp2 installed
trying to go sp3 but when i try to install sp3Setup, downloaded from official site,
i got an error from windows installer..

tried to find a release with sp3 already but no luck.. sp2 at most.

do you know how to install sp3 or where i can find a mudbox sp3 release, please?

thanks alot for your help and time