Problems after upgrading Windows 7 to Service Pack 1

Hi,
I am a user of Windows 7. Recently I heard that Microsoft has released Windows 7, Service Pack 1. So, I wanted to try it and install it on my PC. But after installing this, I am having a problem with my PC.
The problem is, if I give a high load in my PC, it restarts, showing Blue screen error. I also can’t install Games for Windows Live & play games using it. Please someone help me. Thanks in advance.
