Shut computer down to update, came home and it won't turn on

I was playing a few games on my XPS 625 and when I went to start up MSN I noticed my computer had the symbol where my shutdown button usually is that said it needed to shut down for updates, needing to go to the store I clicked it and headed to the store.
When I came back my computer was off, as expected, but when I turn it on my screens do not unhybernate and my mouse doesn't light up, my computer runs for about 10-20 seconds and then it starts beeping 6 times in quick succession and then it stays quiet for about a second and then repeats, I took out the CMOS battery for about a minute or two and put it back in, as well as taking out many of the parts and air-canning out as much dust as I could and it continues to beep when I start it up, any ideas how I may fix this?

Was there a lot of dust inside the case? You might want to remove the memory and re install it...

After deep cleaning it there was a done of dust in it, as well as dust balls.
I usually just sprayed out key areas with an air can.

But by reinstalling it do you mean just pulling it out and putting it back in? because I think I've tried that (Sadly)

6 short beeps In most bios .Are keyboard failure. Try swapping out your keyboard. If this dose not work you may have to have the chip on the main board for the keyboard replaced. I hope this helps you.

Yes that's what I mean... If you are using a PS2 type keyboard, remove it and try a using a USB keyboard