My computer wont finish Downloads!!!! WTF????!?

Okay, it's Christmas and i got a ipod touch and i have to download itunes on my PC to register it on there, Problem is that IT WONT FINISH FREGGIN' DOWNLOADING!! this is what it does...*ahem* it'll start as usual (all good and stuff) download then right when it gets to 99% it freezes and like says verifying *blah blah* and stays like that for like 15 mins. and then clicks off no warning no pop-up saying error...nada....Therefore i never recieve the download as if i never did and i've done everything plz for the love of my lord Help Me!!!!!