When you have a grub prompt, it said Grub has already got into the MBR, which is a good news. However Grub does not know where is the partition to go to, something is missing or not properly installed, so Grub gives you a prompt and wait for your instruction.
Assuming your hard disk is good and the rest of your installation when well, then just try these steps :
1. at grub prompt type
find /boot/grub/stage2 , then <enter>
you should see a list of (hd0,x) that contain partitions with grub stage 2, which is where the grub is installed at your partition that house your antiX, I have multi boot so I have a few there, you should expect only one line, you will use that line for next command:
grub> find /boot/grub/stage2
(hd0,5)
(hd0,6)
(hd0,7)
(hd0,8)
(hd0,11)
(hd0,16)
grub>
2. Next command is grub>
root (hd0,5) then <enter>
you should see a line below Filesystem type is....,
grub> root (hd0,5)
Filesystem type is ext2fs, partition type 0x83
grub>
3. Next command is grub>
setup (hd0) <enter>
grub> setup (hd0)
Checking if"/boot/grub/stage1" exists... yes
Checking if"/boot/grub/stage2" exists... yes
Checking if"/boot/grub/e2fs_stage1_5" exists... yes
Running"embed /boot/grub/e2fs_stage1_5 (hd0)"... 17 sectors are embedded.
succeeded
Running"install /boot/grub/stage1 (hd0) (hd0)1+17 p (hd0,5)/boot/grub/stage2
/boot/grub/menu.lst"... succeeded
Done.
grub>
4. If you see the above you are in good shape,
final command is grub>
quit <enter>
You will be back to the root prompt
[root@localhost ~]#
5. Reboot .