hmm.. 2 things.
try to get the windowsXP 64bit BETA.
and your graficscard looks like an 'onboard'thingy. so its not that good at all.

anyway u can turn that autostart interceptor off somewhere in the menu

to answer that question bout your sound problem we could need infos about your soundchip/-card

 

yea the gfxchip might be good for that games, but it is known that the most games are made for radeon n gforce cards. most bugs or choppy performance is then based on that i guess.

to the sound thing.... maybe its not a 'windows' problem. try to update your mainboard drivers. that realtek chip is well known and supported, u can download the driver for that chip nearly everywhere. just try google or somthing with your mainboard type or specially that soundchip type and u get some links for them.

maybe that could solve the problems.
and, keep your windows up to date through their updatesite.

close all applications that are not needed and get some progs for spyware and adware. maybe somthings running in the background.

I did that and now the slow downs have stopped.