Righty.... You're not the first I know with TT issues.... change providers to PlusNet it's easily done these days, and you won't lose connection.
Install Spyware Doctor free with Google Pack , and run a FULL SCAN. Delete anything it comes up with.
Now clean up you're computer. In Accessories>SYSTEM TOOLS .... find DISK CLEANUP and run that... delete everything it comes up with. Then before you go to bed run the DISK DEFRAGGER ... and let it run over night.
Putting an extra 1GB of memory in can help speed it up, how many do you have now?