Error loading operating system

I had just finished installing openSUSE 11 when, after restarting my computer, I was met with this error message:

“Error loading operating system”

I’ve already double-checked the .iso I used to create the install disk, and I’ve also checked the disk itself. In addition, GRUB has definitely been loaded and I’ve tried to load from both the root and boot. I’ve used the automated repair function off the disk, but that didn’t help.

My System:
Lenovo T41
40gig hd
1024 RAM

I have a good deal of experience with UNIX, but am still fairly new to Linux. During the installation process I just stuck to what was recommended by the installer. I’m not duel-booting with any other OS. Any help I could get would be great, thanks.

Re boot with the disc
Repair as expert the Bootloader and MAKE SURE GRUB IS ON THE MBR

My guess it’s NOT
Look very carefully!

It is not clear un me:you mean that grub loads successfully and since then the os is not found or grub is not loaded at all?

Thanks caf4926, that was it. GRUB wasn’t on the MBR after all, it was a very stupid thing to miss on my part. Thanks for your help.