Nightly Computer Crash

So, the past three mornings I've awakened to find that my computer "did not shut down correctly." That is, the computer is off, and when I hit the power button, I get the Safe Mode option screen. I have no idea where to even begin looking for this culprit. Could it be my power settings (I have a W-7 Pro 64 bit system, and it's set to "Balanced" ... the preconfig'd powers setting)? I've had this computer over a year and it's never done this, so I'm not sure if it's a new install (although I've not added any programs, but have updated a few) or what.

Any ideas where you'd start to look for this villain? This is a new one for me. Everything seems to be running fine once I'm back up, but it's happened every night after I've gone to bed, which is why I suspected power settings, but ...

Thanks for any suggestions you can offer!

Welcome
Several steps to help diagnose.
Run and upadated and complete anti virus scan
Download and run a full scan with malwarebytes.
Before going to bed set the computer with a clean boot.
http://support.microsoft.com/kb/929135
Unistall from the net. Unattch the modem, do not just turn it off.
Do these one at a time, to know which procedure prevents the problem.

Richard,

Thanks for your prompt reply. I do weekly complete virus scans, but will do a manual one today, as well as with my Malwarebytes. When you say "clean boot" do you mean just do a reboot before bed and then let it sit?

Follow my instructions in the above post for a clean boot. Then after it is set up in clean boot, just let it sit overnight.

Ah, never mind on the "clean boot," I see the link. It didn't show up on my email notification, so was asking prematurely. Will try this out ...

BTW, I came home today after being gone for a few hours, and I had the same problem, so I'm really suspecting my power settings ...

It may very well be the power settings. You may want to reset it as another test.
http://www.sevenforums.com/tutorials/778-power-plan-settings-change.html