I installed Linux Mint last night, and today, managed to corrupt the grub partition (I think). When I boot, I get the grub prompt (and some error message, I think). Right now I’m booting off the Mint CD. I have the Ubuntu 9.04 live CD also, if that helps.
I’ve tried to follow directions on repairing it here and here . I can’t follow the first, and for the second, Step 3: Install GRUB to the MBR: doesn’t work. For the first link, find /boot/grub/stage1 doesn’t work either.
I’ve gone partway through reinstalling Mint, but it wants to install another partition of Mint, not overwrite the existing one. There didn’t seem to be a way to tell it to overwrite the Mint partition.
If it helps, the partitioning from the first step of the second link is given below.
sda1 is Windows XP, sda5 is a FAT partition, and sda7 is an existing Ubuntu partition.  I don’t want to harm any of these partitions. sda9 is the new Mint, which is only marginally altered, and may be sacrificed.  I guess the others are swap partitions, or maybe one is the grub partition.
mint@mint ~ $ sudo fdisk -l
Disk /dev/sda: 120.0 GB, 120034123776 bytes
255 heads, 63 sectors/track, 14593 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x0004fa98
Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1        3560    28595668+   7  HPFS/NTFS
/dev/sda2            3561       14593    88622572+   5  Extended
/dev/sda5            4866       12160    58597056    b  W95 FAT32
/dev/sda6           12161       12409     2000061   82  Linux swap / Solaris
/dev/sda7           12410       14496    16763796   83  Linux
/dev/sda8           14497       14593      779121   82  Linux swap / Solaris
/dev/sda9            3561        4803     9984334+  83  Linux
/dev/sda10           4804        4865      497983+  82  Linux swap / Solaris