I got myself a new PC last year thanks to being in much the same position. Rock-solid HP Brio, running Win98 but the gfx card was a mobo-mounted Rage Pro, with no way of upping the video memory...

Only after getting this new PC and discussing things (in a Teamspeak server - great for sorting out tech problems in real time) with a tech-head online pal did I find out that it IS possible to add a gfx card and disable the mobo-mounted board, in the BIOS.

Not sure if extra cards are even an option for a laptop. Latest vid cards are coming with their own cooling fan so a tower case and good ventilation space around them are taken as given.

In my situation it was worth the new PC in any event - skip a few not-so-great Win versions and go straight to XP. The CPU was nearly 10x faster too!