Window Vista 64-bit

For internet surfing, it shouldn't make too much difference. Vista may be safer. I don't even use anti-virus (had norton anti virus but it made some video choppy). I still think vista feels slower for games; 4 gb will help some. Vista files take up 15 or more gb of space versus maybe 6gb for xp. Can't tell you about software media dvd; sounds like a gimic. If your pc is working smoothly, I would stay with xp as long as security updates are available. Microsoft promises 10 more years of support for xp. I use vista as it came with my new compaq. But I stuck with windows 2k pro on my spare pc. Vista was slow to install my internet software; it took up to 5 minutes for internet access due to the device driver order of install, so I went back to 2k pro. Bottom line: my celeron 430 with 2k pro is about as fast as my vista with an overclocked e4300 dual core.

it is DDR2 533Mhz