Xp Home blue screen

Im having a problem with windows xp where it wont boot up.. i get a blue
screen and then the machine just restarts itself.. i did write down the error
numbers it gives but i have left them at home.. anyway i tried a repair
installation by booting from the cd but i only get as far as loading the
drivers for setup and then the machine restarts itself.. i can access the
bios but have no idea on how i am going to reapiar or even reinstall
windows.. can you boot into dos from startup??
Was thinking i could maybe format the drive that way.. also the machine wont
load in safe mode either.. just restarts

Any help is extermly appreciated!!!!