Sunluxy 8CH DVR HDD Not Found

Hi, I got a sunluxy 8 channel system with DVR (http://www.ebay.com.au/itm/CCTV-8Channel-DVR-4-Outdoor-Home-Video-Surveillance-Security-Camera-System-500GB-/190837293703?) and when I got the HDD it said it needed formatting. So I formatted it on my pc, not the DVR (nooby mistake :S).

Now when I plug the HDD in it says HDD not found, i've tried deleting the volume off the HDD again on the PC and no change.

Any help would be great

Thanks.

Re format the drive in a basic dos format, plug back into the DVR it should reformat automatically.

Its not recognized just now because it was probably formatted in something other than a basic format.

That was completely unnecessary as the DVR is perfectly capable of a format.

Which format would you suggest as a basic dos format? I've tried both NTFS and exfat, which come up as options in windows 7.

I've also tried deleting the volume completely, which didn't work. I then tried assigning a volume without a format which also didn't work.

Thanks.