starting problem

I have a Sony RS422, with Windows XP. When I start up now, various start up options appear but do not work. (The screen remains frozen). I can access the BIOS set up screen, but after loading default settings and existing I am running into the same problem, – windows will not open up in any mode. I think I am missing a key sequence here, since a preliminary check of all parameters in the BIOS set up looks oky. I did not make a copy of the system recovery disk. Any ideas.