A recent hardware or software change might be the cause to fix the problem: 1. Insert Windows installation disc and restart your computer, 2. Choose language settings/NEXT, 3. click repair your computer. If you do not have this disc, contact system admin or computer manufacturer. status OXCOOOOOOf the boot seletion failed "a required device is inaccessible
So, what have you done - any of what you posted ?
If you don't have the Win CD, there are (or should be) restore procedures for your make / model computer.