Uh..., yes, some tool bars was installed in IE7, but I don't think it is the main reason. Now I am using firefox, and also installed many toobars I need, it works well.
I've always used IE, but with IE7 I noticed it ran pretty slow on my computer, maybe its just my computer, which is why I'm on FF now.
maybe you can just ignore it and install another browser, it is easy. and set the new browser as Default browser.
If you can run IE 8, I recommend you upgrade. If you can't, I suggest you look at Chrome, Firefox, or even Opera. It's worth testing your sites in IE 6 and IE 7 (lost of businesses still use them), but I'd not recommend them for day to day use.
It seems most of you use Firefox. But try Chrome and you will see that it is faster and better than FF or IE. At the moment its like this: Chrome - Good browser, Fast Firefox - Good browser, Slow IE - Bad browser, Slow