Computer shut down upon start Problems

My computer shuts down twice everytime I start it.
Then at times it is hard to shut down.
It also shuts down on its own at different times.
I have also ran spybot and a registry cleaner. I still have all these problems.

I have replaced and cleaned all fans replaced my power unit. I am at a loss.

Please help.:cry

Thank you

 

Anyone can you please help thanks,

 

Does it shut down before or after the desktop has loaded?

Also, you might want to try:

- An antivirus scan if you haven't already. Try use Dr.Web's CureIt for the scan on safe mode. It takes a hell of a long time to scan, but if its a malicious software problem like a hidden virus, itll be sure to find it.

- It could also be ur ram, try cleaning the contacts of ur ram with a damp cloth. I had this problem when I replaced mine without properly dusting the seats, my computer kept on restarting itself at random times without warning.