Well, my XP 32 bit can handle 3,5 GB RAM, soo...
Anyway, i have problems with the trainer crashing and/or locking up the game too.
It isn't possible -.-
Link
I would explain it exactly if my english would be better.
Anyway if you change something in your registry that it shows you have 4GB it just can adress 3GB also you can't use 1 GB.