I don’t know, but I’ve recently figured out why Firefox is better than IE8. All the information I could find said Firefox is better, but most of what was said had to do with security. Here’s a performance related testimonial.
I’ve used IE8 exclusively up until about 2 weeks ago. From time to time my laptop would just slow to a dying crawl. I had 2 problems, McAfee... it’s garbage, and IE8. I’d run taskmanager and see the two of them just killing my system. I disabled scan on access and now McAfee is tolerable, (it’s provided by work). But IE8 would sometimes just go bonkers. Best I could figure is a memory leak, because it would get worse as the day goes on, and I tend to open and close tabs. I did all I could, and finally just tried Firefox. MUCH better.
IE8 is a pig, and there’s little reason to expect IE9 is better. Go with Firefox. In the past installing add ons into Firefox was a pain, it’s just as easy as IE now.
Use the following 2 programs and it should clear your computer issues. I’ve been using both programs for over 5 years on both my computers. I have zero issues. It will help everything run like day 1. Including your McAfee.
CC Cleaner (It’s free, but they will ask for a donation)
http://download.cnet.com/ccleaner/
Advance System Care ($19 a year but well worth it)
http://download.cnet.com/Advanced-SystemCare-Free/3000-2086_4-10407614.html
Good luck!