128 is low, but probably passable. 256 is certainly better, 512 nice but not necessary. I have 1024, but I do audio/video editing and multimedia stuff, etc., and games.
Upping your ram won't increase your download speed. Probably. You never know with computers, but . . .
If you wanted to increase your ram, you would need to buy a "stick" of it. Which kind depends on your motherboard. Or you could ask a geeky friend to do it.
RealPlayer: don't recommend it. Avoid. Quicktime or Windows Media Player is the way to go.
Hey Buddy, do me a favor: go to http://www.numion.com/YourSpeed/
. Make sure "Measure your speed to websites in: " is set to "The World", and then click on "Start!" Then give me the "Throughput" numbers. FYI, my numbers were:
Throughput: 58386 Bps / 467 kbps