Well did that work.If not you can try booting using boot flopy and check msdos.sys and see if someone has palyed a trick on you.Check if the keywords "bootkey=0"and"bootdelay=0"or some similar keywords are there.If yes remove those keys and save.Oh just before doing alll these save the file in a safe location.After saving check the size.it should be greater than 1024 bytes.if not restore the original file and boot.If yes boot and now try to press F8 or ctrl as specified above.