Apologies if anyone else has posted this, I didn't find it when searching the forums. Boot a live cd, I used a PCLOS '07 disc I had handy. Click My Computer, System, your root partition. Root directory/desktop/repair mbr link on desktop. Run it, close/save the conf. file it shows, reboot.
It worked for me anyway, I could find my ubcd and didn't want to download it again..