It's not your pc hardware or SP2, could be your dsl/internet connection. Do some upload/download speed tests at DSL reports to get an idea of the speed of your connection to rule that out. You have a very nice pc with a fast processor and gpu. Is it only internet that is slow? Could be some malware slowing it down too. MAke sure you're running up to date AV and anti-spyware software through a firewall.