PC won't start after Windows update

So, did the Windows update that came through last night and when I woke this morning, I could hear the hard drive spinning but nothing on the screen. I tried to "wake it up" as I have it set to Sleep. Nothing. I tried to force a shut down by holding the power button and it wouldn't shut down...the whole time you can still hear the hard drive spinning. I eventually unplugged it and let it rest for a while. Plugged it back in and restarted it. The back light to the monitor came on and the hard drive started. then after about 30 seconds or so, the screen goes black. Hard drive continues to spin and spin. Nothing else happens.

In the case of full disclosure, this PC is about 5-6 years old. It's a Dell Inspiron All-in-One. (forgetting the #'s right now (3250 maybe?), but it was the first one they put out). It did have a power issue about a month or so ago, but our local PC shop fixed it and it seems to be running fine...it did until last night.

Any thoughts?