Windows 7 Explorer (and other software) hang, seemingly at random

For the past few months my desktop has been performing poorly, in that Explorer frequently hangs and I have to either restart Explorer or reboot the entire computer. Other software also hangs from time to time, such as 3ds Max, Opera, Outlook, etc, requiring me to use Task Manager to close them. Sometimes CTRL+Alt+Delete doesn't bring up the menu and I have to hard reboot by holding the power button.

I read online that Explorer hangs could be caused by shell extensions, but with other software hanging as well would this still be the likely cause? I do not have that many installed other than things such as TortoiseGit/SVN, Notepad++, and a few others. As of late I've been rebooting my PC several times each day.

I also ran a scan for malware using both Malwarebytes Free and MSE, and both turned up clean.

System Specs (Stock Dell XPS 8700):

3.4 GHz i7-4770
12 GB RAM
GeForce GTX 645 1
1 TB HDD
Win 7 Professional x64

Does anyone know a good way to troubleshoot what might be the cause of the system not responding?

I followed the instructions on the linked page and ran the scan. It completed successfully and said that there were no integrity violations.

After the most recent hangs I looked in the Event Viewer and certainly some error messages were visible but I was not able to figure out what was wrong by reading the log info.

Additionally I used ShellExView to disable all non-Microsoft shell extensions, and so far things seem to be running smoother. it may have been a bit overkill to disable all of them but for the time being I haven't had more hangs since rebooting.

Would it be helpful if I were to post the error messages from the Event Viewer here?

I will follow the tutorial above and see if it helps. Also may try re-enabling shell extensions one by one and see if anything changes.

Here is the event log from when my system was hanging. One of the events marked as critical is when I held the power button to reboot.

error_log_2-21-16.zip