I think the XP workarounds for SS2 are very hardware specific, they work on some machines but not all.
For guaranteed success getting SS2 working again, best to use Win98, for this reason I've built a cheap Athlon 1.4 dual boot 98SE/XP 512mb ram, geforce 3 in my bedroom for older games in 98SE and general surfing in XP.
The high res texture stuff for SS2 seemed a bit buggy to me, a lot more game crashes, but part of the appeal for me, is playing these old games as they were when they came out, SS2, Thief Gold, Thief 2 and Dues Ex all have great repeat playability due to the many different ways you can play them, all I've done to mine is mod them to a more suitable resolution for my bedroom 17" LCD monitor and use a Logitech MX518 for good mouse response.
If you think thats sad, I've also built up an old P200 64mb Dos6.2 box that shares this LCD monitor via a KVM switch, this is used for the original System Shock and Ultima Underworld and Ultima games when i feel like a bit of nostalgia
