there are literally hundreds of reasons why your computer might be slow. you will have to post your system hardware and what version of Windows you are running to see what might be the cause. from what little you say though, it sounds like you have both a virus and spyware running on your system. you need to run an antivirus program right away and then look for Adaware by Lavasoft to clean up the spyware. if you don't think you can do this yourself, you should take it back to the place that replaced your hard drive and have them help you.

Herb...