3 reasons: too cheap to upgrade, games and our main client at work requires our stuff to run on it.
It has an agp graphics card.
Have you tried upping the AGP voltage to 2gb tbh?
Glad you mentioned that. Another reason to not upgrade: ram is maxed out @ 2G. I'll probably be buying a new barebones kit in another year or two, and get Win7 oem/jim*.
*Jim Intentionally Misleads
What's the cpu?
Win 7 runs fine on 2GB and a relatively slow (by today's standards) Core Duo (not Core 2 Duo) mobile cpu.
I use it at work. Can't say it's noticeably better than xp.
It manages memory better than XP and so usually feels faster (i.e. is more responsive) on limited RAM.