Invalid System Disk?

my dad ran diskdefrag the other day and it looked as all to be well but when i restarted the computer i got the error message:

invalid system disk - press any key to continue

after pressing the spacebar it boots normal.

i guess its not really a big issue but i would like it not to be there...any ideas

you can get this message if there is a floppy disk in the drive.

i dont have a floppy drive...i dont have anything in any drive

hi,

if you put the message in a search engine you will get more possible causes for the error message.