This command will execute the program 1.BAT which will, in turn, 
execute the program CHK_STER.EXE. CHK_STER.EXE is a machine language program
which will display the boot record of a disk in drive A. The disk does not have
to be bootable. 

If the boot sector contains the message, "This PC is stoned!",
then the disk is contaminated. 

For a computer infected as described above, you may remove the virus by
following the instructions displayed on the screen by the program. If you
select to remove the virus, it will be removed by taking a copy of a good
boot record for MS-DOS 3.3 and copying it over the virus in the boot sector.

If the disk was originally bootable, it will no longer be bootable unless
it was originally formatted with MS-DOS 3.3. The disk will however be useable
and it will not have the virus. 

   - When the menu reappears, the virus will have been eliminated from 
     an infected floppy disk. You may check the disk once again
     by entering the command:
     A:> 1