Hang on, win98 doesn't have sfc?
Are you talking about scandisk?
Straight from Computerhope help files.
Question:
How to enable / disable scandisk from running after improper shut down.
Cause:
Versions of Microsoft Window 98 and later are designed to automatically run scandisk after the computer has been improperly shut down or rebooted. This is done as a safety measure to help ensure no data corruption occurred during the improper shut down / restart.
Answer:
This feature can be enabled or disabled in the msdos.sys file by changing the AutoScan= section. Additional information about the msdos.sys, hot to edit it and its values can be found on our msdos.sys page.
MSDOS.SYS
AutoScan= Allows Windows 95 OSR2 and above to scandisk the hard disk drive if the computer was improperly shutdown. The default is 1. Setting the value to 0 causes the computer to not scandisk the hard disk drive. Setting the value to 1 prompts the user for scanning the hard disk drive (scan begins if no input for 60 seconds). Setting the value to 2 allows for automatic scanning (no prompt).