Can you help me, because my Internet browsers are sometimes refreshing by itself, so what internet browser is much better to use?

I was planning on buying a new video card – Geforce 9400gt 512mb. It was around 40 bucks but it said Low Profile in description. How are Low Profile cards worse and Is it worth getting it. I’m using 8500GT now. Computer is primarily used for gaming.

2 identical 1GB memory sticks in a dual channel configuration. How much will my computer recognize?