Screen goes black no input half way through boot

Hello, I'm having this issue with my rig. It's happened to me before and I replaced the graphics card which fixed the problem. Now I'm wondering, since this is the 3rd time it has happened and the card doesn't seem to be bad (see details below), if it is some kind of software problem somewhere.

The issue is this: When the computer is working normally, the mother board POST screen splash only displays for about a second, then I hear a beep, then the computer would commence loading windows. Now, the post screen stays up for ~30 seconds like its stuck, then it beeps, then it goes into loading windows after another bit of a delay.

So problem #1 is slow startup/POST way out of the ordinary.

Secondly, during windows start up I see the 'starting windows' and the windows flag appear (Windows 7), but after a moment the screen goes black and the monitor acts as if there is no input. If I wait 30s to a minute or so, the screen comes back and I have my normal user log in screen. I am then able to log in to windows normally, and I do not appear to have any performance issues. I can go about my business, play games, etc as if nothing is wrong.

So problem #2 is loss of input after windows flag/before windows log in that returns after a time.

As I said I had this problem in the past. Before, I was using 2 older graphics cards that I had crossfired/SLI (can't remember which brand they were at the moment), but I suspected 1 of them went bad because it wasn't moving as much air through it as the other. When I removed the one I suspected was bad, the problem went away entirely. Then a couple months later, the problem returned and that is when I replaced the card with a new GTX 660 from best buy. That was about 15 months ago and everything has been fine since.

I have already tried uninstalling the card through the device manager and then reloading it next startup, deleting redownloading the card driver, updating the driver. I can get to safe mode after the slow POST and I don't get a loss of display input. I have windows update turned off because 1 time this issue happened was after windows update decided to update my card driver for me, but I was able to fix it (can't remember when this happened, if it was before or after the GTX 660 card was installed).

The only other piece of information I have is that the issue seemed to happen the first startup after a power outage. I'm on a good surge protector (I know still not 100%). Usually I shut the PC down everytime I'm done using it, but I haven't been using it a lot and my wife has been using it a lot more than me for work stuff the past few weeks so it is usually almost always on but logged of and in sleep mode. This is the state it was in when the power went out. Is it possible the power outage could have corrupted some other driver or maybe the motherboard bios or something that is causing this? I noticed in the device manager that I also have a USB driver with a yellow exclamation point that I don't remember seeing before. My MOBO does not have on board graphics so there is not a competing driver problem.

I'm at a loss for what to do right now, and I would rather not replace the graphics card again if I can fix the problem because as I said the computer seems to work just fine once it finally starts up and gets into windows. It seems like its more of a driver loading problem. I greatly appreciate any suggestions to try to fix the problem.

Thanks!