My old PC is Intel III 498Mhz, 128MB RAM, 8GB, Rage graphics card and it's still kicking...though kicking very slowly. I had to resurrect it countless times. But your comp can't run XP? Mine is worse that yours and it had XP Pro since it was released. It gave new life to my dusty piece o' crap.
IE works fine for me, and the only reason it lets in Adware and Spyware is because you have programs that run the ads. It doesn't work with Firefox because it uses a different algorithm then IE.
I used to get popups all the time from programs like WeatherBug/PrecisionTime/Kazaa but once all that is removed, or you pay for them.... IE runs fine with no popups or nothing, at least for me I got NOTHING popping up on IE... and right now I still believe IE is the best browser to use until Mozilla releases a much better Firefox because it still has bugs.