For what seemed to be very good reasons at the time but with hindsight, monumentally stupid (but hey), I reformatted the disk containing my linux partition, including (hah) the boot partition. I then rebooted my machine, presumably (since I am now in denial) in the naive hope it would just boot into windows

.
OK, so given that (1) the damn thing just sits at the grub> prompt refusing to do anything useful and (2) my windows rescue disk is now claiming to be corrupt and won't boot (

) BUT I can get into BIOS (whoopy doo) can anyone suggest anyway I can resolve this without actually obtaining a new OS and completely reinstalling.