Hello mate,
you can try that msconfig thing.
also you can disable everything on that except the antivirus and you'll be up and running.
also if you'de go to
c:\windows\prefetch
you'll see a lot of files there delete all of tyhem. it is a temp folder of windows so just delete all of them and do it regularly and just notice the performance difference.
also you said that you formatted the HDD make sure that you have not done a dirty installation other wise it might not work properly..
boot from the cd and you'll be running fine.
do that prefetch thing and it does work wonders
GOOD LUCK.