Don't you just love it when computers do this?
It sounds like it can't boot up successfully, so restarts to try again. Then, when going, it detects a problem and wants to correct it by rebooting-which is the usual way of correcting some things.
Could be a program that is causing it. Have you added anything new?
Do you have a restore point that you could go back to and try? This is always a good practice, so i suggest that you do it once it is running OK.
Failing that, I would be pointing a finger at the motherboard-it may be starting to fail. If that is the case, it may be terminal....

There's no point in talking naughty to me Peter, 'cos it's all pigeon English or whatever to me. I have no idea what a terminal or a mother board is! Sorry

I made a list of every single program running in the background as per 'processes', but I have no idea which are vital and which are not. With my luck, I'd delete the one and only process that kept my PC running....

I have an addit.

I went through all the 'processes' and I saw sweetIm in there, taking up over 6,oooKs . SweetIm is a program that I downloaded ages ago, didn't like, and uninstalled. How do I get it out from using up those 6,oooKs in my processes?