Cant get da Bois

[sanjayk111]

Hey i have an asus m4a783m/1394 mobo...
i had overclocked my cpu frm 3.0-3.3ghz.......
now while system boot whn i press del or Tab the bois doesnt come up....It shows msgs like "Run windows normally" "safe Mode"
or smtimes "boot priority"
wat shud be the problem ??

 

[sanjayk111]

my pc boots perfectly n is running fine....just dat i wanted to take my cpu back to normal 3ghz... n i cant access da BIOS