Cleaning computer messed up my computer

[solitary1]

So i was cleaning the dust out of my computer today, and when i went to turn it on. It won't load windows! I get to the screen where it says whether or not you want to boot safe mode, last known good config., or start windows normally, if i select last known configuration the screen goes black and doesn't load anything.
if i select start windows normally the screen freezes.
if i select safe mode, it loads and then freezes as well!
did i touch or damage some hardware? how do i find out help!!!!1!1!!

Thanks in advance.

update: 5 mins after posting this it started loading widnows and is currently performing a system scan. we will see how it goes
update2: it is working now, i dont know what i did though.

 

[Atomic Rooster]

Go through and make sure all your cables, wires, connectors are firmly in place.

 

[solitary1]

i checked all my connections, the computer just randomly restarted itself, and then it went to the blue screen of death, saying it was performing a physical memory dump? and it started counting 1....2..3..4.5, so i restarted and physically checked all my connections, everything seemed good. Is there something i can do from preventing this from happening again?

 

[Atomic Rooster]

Well, first of all, you should never mess around with the cables and wires while the computer is running. Bad things could happen. Always shut it down and unplug it from the wall when working inside a computer.

I figure you just bumped something inside your computer while cleaning it. The best way to prevent anything like this happening again is to just be careful and safe while working inside a computer.