Windows 7: System locks up. Can I track with logging?

My system periodically locks up. I can still see the desktop, but the mouse is frozen and the time and date are also frozen. I've tried swapping out the power supply, getting rid of extra hard drives, checking memory, reducing the size of memory, deactivating software that might be causing problems and were installed around the time the freezes started, but nothing works. Is there a way I can set up some sort of system log so I can look at what the system was doing when it locks up, to troubleshoot the problem? I know I should have done this first thing, but I thought I knew what was going on and eliminating the cause seemed like the way to go. But I don't know the cause, and need some help finding it.

I installed the debugging tools, but have no idea how to initiate the logging process so that there's a *.dmp file to analyze in the event of a lock up. I assumed installing the debugging tools would do that, but it hasn't.