When I switch on my old PC, it seems to boot ok but when it tries to load windows it suddenly restarts, therefore entering a continual loop. Does anyone know what might wrong?
We need some more details, what windows you using XP, Vista or even 98 or 2000. There can be a few reasons why it abandons the 'boot' process and tries to restart.
I had this a little while ago and it was caused by a corrupt system file and I had to re-install XP. But there are other reasons as well.
Have you got the Windows install disk and did you make an emergency 'boot' disc?