Computer keeps restarting and does not go into windows

Hey something happened to my computer a few days ago. I haven't downloaded or installed any new programs for the past couple of months.

My computer was working fine, when suddenly it reset itself. When i now turn it on I am given a screen which asks me to choose from the these options if I want to load windows:

safe mode
safe mode with networking
safe mode command prompt
last known good configuration.
start windows normally.

None of these options work it goes to the XP booting screen then goes back to starting the whole process again.

Any ideas I don't have the disk to restart everything and I can't find a download from Gateway to do so either. I have also tried searching the net for a restore disk and no luck there.. I don't know what to do.

Can anyone help me please?