Problems with Windows 7 startup

I've had my computer for around 10 days, and since day one I've been having trouble when I log on. I can boot into safe made fine, and the log on screen works too. It's after I've logged on when the problems start.

Once I've logged on, all the icons appear (apart from the volume, connection etc.) and everything glows when I hover over it. After a few seconds, everything becomes unresponsive and there is no glow when I hover over the icons (sometimes I receive a pop-up saying Windows is not responding). After 10-20 minutes, everything starts to respond again and my computer works fine. How can I fix this?

My PC specs:
AMD athlon II X4 645 processor @3.1GHz
Radeon HD 5670 1GB
4GB RAM
Windows 7 home premium 64bit

I've already tried reinstalling Windows, but that failed.
My computer is still under warranty.

Thanks.

Welcome to Windows Seven Forums.

As your computer is only a few days old you need to get the manufacturer or reseller to repair or replace it or refund you the cost of your machine as it is obviously not fit for purpose.

Anything we suggest here could well invalidate your warranty.

You really should take advantage of your warranty while it's still in date.