Have atleast 1gig of RAM and a 256MB Vid Card, DSL Connection, make your monitor refresh rate 70, 75, 80 Hz.
Also try making your ingame resolution lower, try 800x600, and make everything low or disabled esp bloom effect.
If it is less laggy, then increase the resolution up one by one etc and also turn on the other options, fiddle around which options lag your pc.
Good Luck
