Stuff like that. Updating video drivers is always the first step, which means getting the correct driver for my card and installing it, which somehow often takes much longer than it should, but usually doesn't solve anything.
To stop Starcraft 2 from slowing down to a crawl after 5 minutes, I needed to download a couple of developer tools to get deep into the guts of WinXP and manually overwrite memory allocation. That one took me at least 8 hours spread over three days.
And I am done with that ****! I'm over with it and I don't care enough for PC exclusive games to put up with that anymore.