Now that you explain it's lookin for an MBR disk then we can hear you a little better. Don't expect us to read your mind.
We'd assume if you have a Win8 PC which you also don't divulge, that it is already set to UEFI with Legacy BIOS or Compatibility Support Module disabled. Check that now in BIOS setup.
In fact I'd reset BIOS to defaults if you actually have a UEFI BIOS, which you've also never clearly stated.
The procedure is here to Downgrade Windows 8 to Windows 7.
If there's the slightest tone of rudeness going forward on your part, you'll need to take it the shop where they get paid to put up with that. We are volunteers who don't have to.