PUT YOUR WIN98 CD IN THE CD DRIVE 1.) click START - RUN,TYPE IN sfc and hit enter 2.) click 2nd option " extract one file from installation disk" 3.) in the box type in C:\WINDOWS\COMMAND\SULFNBK.EXE 4.) IN THE EMPTY SLOT TYPE IN D:\WIN98 D OR WHATEVER YOUR CD DRIVE # IS, MINE WAS( F:\WIN98) CLICK OK CLICK START WINDOWS WILL DO THE REST GO TO FIND AND SEARCH FOR SULFNBK.EXE TO MAKE SURE IT IS BACK ( MINE WAS)