Since i got firefox 3 i have had a lot of problems. PC being slow and taking forever to change sites. The old one is great and nothing has changed on my PC since I downloaded it
Thanks

Nothing wrong with firefox.

Run diskfragment and clean up.

Also run antivirus

I doubt that it is Firefox 3 that is causing these problems for you because it works just fine for the majority of people and it even uses less memory than Firefox 2. But if you want to make sure, you can download Firefox 2 at filehippo.com and see if that helps. If it doesn't, then it is not Firefox 3 that is causing the problem.