Computer shuts off, and spazzes in limbo!

This is a challenging problem to any computer guru, i really have no answers. All i can say is that randomly- sometimes after several hours, sometimes just a few minutes, while playing a game, browsing, or just listening to music, my computer simply shuts off and stays lit up while making noises as if it were on. The monitor goes black, and the lights on my keyboard and mouse flicker. WAT? The crazy thing is, i thought it was my video card so i took it out- and now it only happens less often! Is it a dying memory module? Is it my psu? Is it the motherboard? Is it some loopy software gone wrong? Virus? Please guys, im running on integrated graphics right now and i cant even watch my movies in fullscreen! I really don't get it. PLEASE help me, my saves are starting to corrupt, and i cant even finish an essay sometimes before something happens! If you do have an answer, give a full explanation. Google hath forsaken me in this case!

 

it's hard to explain. the monitor and cable are fine. when it happens, the screen goes black and says "no signal" and the computer seems like it's doing the restart cycle, however it stays in the startup state- in between showing the American Megatrends bios startup and turning it on. http://www.google.com/imgres?imgurl=http://www.cdrinfo.com/Sections/Articles/Sources/ASUS_P5WD2-E_Premium/Images/bios/boot1.jpg&imgrefurl=http://www.911cd.net/forums//index.php%3Fshowtopic%3D16713&usg=___vOKFEGwIBfgV53kAo1NK7IiJEQ=&h=281&w=350&sz=15&hl=en&start=35&sig2=G-rdxHNsPTRg62w7BDgkXA&zoom=1&tbnid=YIqZZoNRw3e4yM:&tbnh=146&tbnw=182&ei=oOrvTPKaOsSt8AaI1anIDA&prev=/images%3Fq%3Dbios%2Bstartup%2Bamercan%2Bmegatrends%26um%3D1%26hl%3Den%26safe%3Doff%26biw%3D1680%26bih%3D933%26tbs%3Disch:10,532&um=1&itbs=1&iact=rc&dur=305&oei=l-rvTIOtDovKnAfgn9n2CQ&esq=3&page=2&ndsp=38&ved=1t:429,r:10,s:35&tx=48&ty=53&biw=1680&bih=933
So it does not get to showing that on the screen ^^^ that's what i mean when i say limbo, because i really don't know whats going on. It just shuts off windows and goes into a sort of restart loop and stays that way. The lights stay on throught the whole process!

 

hello I think plodr may be on the right track First i would suspect monitor then video card , I'm not a expert with pcs ' but have been around them a bit . really it could be dozens of things so its a process of elimination ., hope you have access to another monitor, if this in not it ,try a system restore , then maybe memory cards , if you have two or more then just take one out a try ,then swap , sorry I don't think theres a easy answer .. my lap top took a dive once and found it to be memory card i just bought !
hope this helps rt

 

ps,, must use only one card at a time or even
size to each slot ..at lease on older systems .. the smallest card must be large enough to run the system or could be very slow

 

Create a linux live cd and run that, I recommend linux mint. You need to determine if it's a soft or hardware issue.

 

that seems like a good option- how would i go about finding the problem once i "install" the linux os? Is that even what im doing? linux is pretty foreign to me