Dub Ginge

Hi, can someone help, brought myself a 1995 3dr Golf VR6 today, 86k from new and only 2 owners, condition is fantastic. But the drivers window is driving me mad, when the window goes up to the top, soon as it reaches it comes back down about half way, have checked all the rubbers, they all seem fine, is it a case of it needs a new motor as it has just been up and down to many times. Thanks Ian