Cant Download itunes

Hello,

I had just received my new dell pc with the windows 7 (64). I logged on to apple to down load itunes with no success. What happens is it starts downloading at about 480kb/sec but slow decreases to about nothing over the course of a couples seconds. I have also tried downloading quciktime and safari and the same result happened. I also went down to msft to download Microsoft® Windows® Malicious Software Removal Tool (KB890830) to see if I experienced the same effect. The transfer rate didnt decrease as fast, but was slowing decreasing over the course of a few minuets? Can someone help me fix this problem?