Hi everyone. I ended up resetting my Firefox to fix a problem (then unistalling and reinstalling), as well as removed my anti-virus problem. After I solved the initial problem, I had loads of viruses, malware and TROJANS. I used malwarebytes and Norton to take care of those problems.

However, my Firefox has never been the same. The typing and scrolling is jerky, the videos don't play without stuttering (yet Youtube videos play fine on it). I have tried resetting, about:config settings, changing hardware format. Disabled my add ons, enabled my add-ons. Nothing is working.

Anybody have ANY advice??Do you have another working computer. Another computer could verify that it is not the Internet connection.
You are using XP. That puts you at a disadvantage. Is you connection wireless or Ethernet ? In some cases XP does not do well with wireless.

Are you familiar with Linux Live CDs? Such distros can boot and run without need to USE hard drive space. They help diagnose hardware and software problems. If the browser works good with Linux, it may mean that Windows is having trouble. But it the problems are there even in Linux, it would means the hardware is failing.
The link below suggest Ubuntu for this.
Diagnose PC Hardware Problems with an Ubuntu Live 

Everything is fine using Chrome and everything ELSE with my computer works fine. It seems to be just Firefox that I'm getting these problems and it was always working fine before this incident.OK. So it was only the browser.
You can get a fresh copy from Mozilla.org
https://www.mozilla.org/en-US/firefox/new/


why not use Chrome?We try to fix issues here...not simply suggest switching browsers...
If you had a Windows issue would you like it if we simply stated use Linux ? ?
Think about it.Have you considered running adwcleaner so as to remove certain addons/toolbars INSTEAD of disabling them? http://www.bleepingcomputer.com/download/adwcleaner/In Firefox you can remove add-ons  and plug-ins you do not want.
Aldo you can download a earlier version of Firefox to SEE if that helps.