What can make a 2.4GHz run like a 486?

The answer would be XP SP2!
Seriously, I just got a new cheapo hp computer from wal-mart, right? And even though I've used every trick I know of (turn off all effects, use the 'classic' windows style instead of the playskool style) the version of XP home runs like shit on it.

A great example of this is when shutting down GTA 3, the computer routinely slows to a crawl, and whatever windows I have open are painfully, slowly re-drawn.

It will take in the neighborhoood of fifteen to twenty seconds for everything to re-draw itself.

I've tried replacing the video card (with an nvidia one), installing windows 2000 isn't an option...so has anyone else had to deal with speed issues on windows? Any suggestions ("omfgbbq run linux!!!1one" isn't on the table, neither is *BSD) on what I can do to make my 2.9GHz respond like a machine which is >99mhz?

Frankly, you don't need 2k or anything like that. Windows XP is made to be run with a minimum of 256MB of RAM. Note, I said windows XP, not windows XP with anything else.
The reason your computer crawls so much after exiting GTA 3 is because it is reading all of the information about the windows on the screen from your page file into your RAM, and freeing that space in the page file.

I would say that upgrading your computer to 512 MB will add an exponential performance increase, but an upgrade to a gig of RAM will likely even alleviate that crawl after exiting GTA3.

Either way, despite the lack of quality if most items you find in the lower-end computers they sell at retail scores, with a little bit of money put into them, you can get a pretty decent machine.

>>3
Not everyone feels like learning a new operating system and compiling a new kernel. The odds of me wanting to do all that work for a self-proclaimed cheapo HP system are little to none. Especially with the crappy driver support HP gives even on windows.