Method 1
Change the frequency set in MA20x.ini back to normal mode.
Example:
Out-of-sync mode Normal Resolution=1280,1024 --> Resolution=640,480 <-- Resolution BitsPerPel=8 --> BitsPerPel=8 <-- Color depth 8-bit BCDrv1280x1024=120 --> BCDrv640x480=60 <-- vertical frequency
Method 2
Run SETUP in DOS mode and select a VGA standard driver to get it going. Then reload the Graphics drivers again when Windows has started up.