antivirus help

[adams]

i had nav2003 running, but decided i wanted to try out some new av software so i installed quick heal and rebooted. then let it update and rebooted again. that time after it goes the memory check and that stuff it says:

non-system disk or disk error
replace and strike any key when ready


how do i get back into windows without re-formatting? re-formatting is only a last resort since there is emails and stuff that i really need.

thanks.