How to stop windows xp from asking to turn off or restart

It sounds like you're infected. Run a full virus scan. Get a copy of malwarebytes if you don't already have it.

I've run a virus scan and it comes back clean, nothing is showing up.
This is a desktop PC I use it just to cyle my wallpapers, I enjoy looking at them. It's updated with windows & virus, not sure why the windows box appears in the middle of screen, like I said its a box that gives the above 3 options. I've also checked the monitor setting to always stay on, it's annoying more than anything else.

Thanks

Check your task manager or resoure monitor for running processes. One of them is sending a shutdown request to the OS. Have you checked the event viewer? It may shed some light on this.

can you explain how to do this, not sure how and I dont want to mess up.
thanks
Kim