Win 7 x64 suddenly freezing, cannot alt/ctrl/del

This started happening yesterday out of nowhere. I have made absolutely no changes to my hardware or even software except last night I installed a brand new antivirus (Bitdefender Total Security 2011).

When playing a certain video game (its very old, not full screen, definitely not graphic intensive) the game will clearly freeze. I am unable to close out of it, and when I alt/ctrl/del i select Task Manager and it will not come up at all. I cannot access hard drive folders, and when I open the internet I have lost connection. This is what is bothering me the most, the computer is still functioning but its cut off access to the network card for some reason as well as nto being able to bring up Task manager. I try to shut down but it gets hung up and I have to manually hold the restart button my computer tower.

The virus scanner found nothing, I am a careful downloader. What is my next step? Is there a diagnostic tool I can have running in case of bad shutdown it will record whats happening? Or what kind of program should I get to find whats going on with my computer? Any help is greatly appreciated.


RAM: 8GB G Skill DDR3-1333 SDRam
VC: NVidia GeForce GTX 460 1gb
PSU: OCZ 700W
CPU: Intel i7 930 2966MHZ (22x135)
HDD: 600GB SATA2
HDD2: 200GB SATA2
OS: Windows 7 x64


*Edit* It happened again while I was editing this post to add in the hardware information. When trying to restart it always says that the program Smart DualBios is preventing it from restarting and I have to click Force Restart, but it still is always hung up while restarting. I dont see this program installed on my machine. I did download it a long time ago but I dont know where it is because I cant find it.

This time, upon restart, my computer would not restart. It turned on for about 5 seconds then shut off, repeating this over and over. I clicked the CMOS button on the back and then it restarted. WTF is going on here??!!