I get tips from a friend several years ago. Maybe this can help comrade that need. Log in to appear after the DOS mode DOS prompt c: > type DEBUG like this
c: > DEBUG
For the next type
o 70 2e 71 o ff Q
On the monitor screen will look like under the c: > DEBUG
o-70 2e 71-o ff -Q
Q typing after you exit from the debugging indicates that you have done. Then restart your computer, press DEL and you always have been able to enter the BIOS.