Boot the system into safemode and troubleshoot from there. If it locks in safemode you have a main component or serious software problem. If it works fine change all your settings to as basic as they get. You would then also delete all the drives for anything none-essential in the operation of the system. Then reboot the system. If it works fine, let Windows re-install each component and see if it fixes itself. If not, you will be able to find the problem as it installs each component. If it loads them all, just select a different driver to unload and reload until it locks up again. Once it lock, you have found the problem and can go from there. Hope this gets you started. Ciao.
Scott