HP AiO Device Object Server error

HI. I am brand new here. Not new to computers, but basically computer illiterate. I just don't get it most of the time.

Our son has been playing games and this has happened a few times and just by messing around, turning computer on and off and doing control/alt/delete getting the task menu up I could figure it out but today I'm going on 4 hours and cannot get the computer up.

We have a HP Pavilion computer with windows XP. I am getting this message this morning:

HP AiO Device Object Server Register Class Objects failed: h Res=Ox800706BA The RPC server is unavailable Maximum Retry Attempts Exceeded

Can anyone help me out? We are supposed to leave for vacation tomorrow and I had a lot of e-mails and stuff I had to get to before we left! Thanks in advance.