Some great advice there from Scott and Apex and if your machine is up to spec you shouldn't be having serious issues. Also Courteney is spot on, it's not a WGT problem.
I play on a 4/5 year old laptop running windows 7 (out of choice) with a decent graphics card , 4gb of RAM and my meter is smooth day in day out. I have re-configured it but have also taken the time and effort to find out what works best for my set up. I also have an 8 year old laptop running windows xp with just 1gb of RAM and I can also play without issues on that.
The point being there is no single quick fix answer, everyone's set up is different and it will take a bit of effort on the user's part to optimise their own hardware. Those that don't know how to do this can learn from the advice here, those that can't be arsed will continue to blame WGT