Welcome
Start with a clean install following this tutorial:
Clean Reinstall - Factory OEM Windows 7
Download the Pre-SP1 ISO file for your version of windows. (Professional x64bit SP-1 in your case)
Avoid the factory bloatware. Go through this tutorial:
Clean Up Factory Bloatware
Do not install AVG. It contributes in crashes often:
Code:
Start Menu\Programs\AVG Public:Start Menu\Programs\AVG Public
Microsoft Security Essentials.
Recommended from a strict BSOD perspective, compatibility & stability compared to other antiviruses/internet security software. It is free and lightweight:-

Warning

Do not start the free trial of Malware Bytes; remember to deselect that option when prompted.
Run a full scan with both (separately) once downloaded, installed and updated.
Install all the latest drivers for your hardware.
Method to find drivers:
Quote:
- search Google for the name of the driver
- compare the Google results with what's installed on your system to figure out which device/program it belongs to
- visit the web site of the manufacturer of the hardware/program to get the latest drivers (DON'T use Windows Update or the Update driver function of Device Manager).
- if there are difficulties in locating them, post back with questions and someone will try and help you locate the appropriate program.
- - The most common drivers are listed on this page: Driver Reference
- - Driver manufacturer links are on this page: Drivers and Downloads
For NVIDIA:
NVIDIA Driver Downloads - Automatically Detect NVIDIA Products
Let us know if you still have BSOD-s after the fresh install.