Check msdos.sys on c:\ after you make it accessible with the atrib command. Also check autoexec.bat. One or both have commands in them that start windows up. Boot-gui=1 in msdos.sys could be changed to Boot_gui=0 and any line like c:\windows\win in autoexec.bat can be commented out. Actually you could probably comment out the Boot_gui line in msdos.sys too now that I think of it. That slows down windows. If the CDROM is set to boot first in your cmos, putting a linux disk into it and telling it to boot with one of the speakup kernels and what and where your screen reader is should be enough to get you started. Good luck with your windows cleaning!
