let me tell you the story from the beginning i had a mutltiboot system -ubuntu,windows 7(pre-installed). as we know there is a loader(the one that give us multi os choice) that start loading from the ubuntu os but what i do here is i just manualy format the partition (on disk manager app on windows 7 ) that has the ubuntu os (not the loader- they are distnict actually) it was working fine until the first reboot that i met with this command for the first time
error:unknown file system grub rescue>
i got the answer for this and try it but it only work to load the linux one and i just already delete all the source files for ubuntu so it couldn't make it. so i tried to get onother linux- fedora16 . amazingly the live cd provided me with those partitons of loaders i formated the partition of what it said 'linux swap space'. and the next reboot message was error:file not found grub rescue>