I use WIn98se and agree... it can be a pain but it certainly gets the most out of older hardware.
With my 3 year old Piii700 o/c to 840 on my Abit Be6 mobo with 256mb and trusty ol' Hercules Gf2mx I get a very respectable and solid I might add 32fps in Gp4 with 3d sound and most things on high except including reduced detail mirrors but not the real killer on my system which is static & dynamic car reflections tho' i still run the advanced car shader.
That is with my own modified/updated version of AveryGP's most excellent and splendiferously spunky big cars.wad that alas has gone the way of things too good to be true (I digress) ... hmmm
Well anyway Win98se rocks on my system and my friends wizz bang XP pro P4 2.6ghz gazzumping machine struggles with Gp4 and although the gfx card is newer and has more bells & whistles I can't see it looks better than mine... but that I spose is no refelection on the PC system but rather the way the game was coded or not , as the case may be.
**** I can waffle on sometimes.... sorry :D