I never had problems playing BG1 or BG2 but I recently decided to try and complete the game from the start to the very end. Now I have a serious problem. After about 5 or 10 minutes (max) the game becomes very slow and choppy, making it rather impossible to play. If I exit the game and start it back up a couple minutes later, it's good again but then it starts all over

.
The thing is, I've played those BG games a lot before on this pc and never had issues... Been playing with the configuration but nothing seems to work. I cleaned my pc (now 100GB free disc space), increased virtual memory, made sure enough ram is available and so on. Nothing seems to work.
Also, it's the same for BG1, BG2 and the BG Tutu version.
I really hope someone knows how to help me out on this.