Q: I tried twice and it stalled both times. Any ideas?
A: Download the offline version of SP3, it should be fairly large, reboot into safe mode, and double click it to install. If that does not work, go into add/remove programs and remove as many updates you can (SP3 will reinstall all of them) and try to install it again. Rebooting into safe mode should do it, just make sure to download the offline update (you should not have to access the net to install it)