recovering erased hard drive with Testdisk Recently I have accidently erased my harddrive with all my old mac files on it, and I have been trying desperatley to get it back.

I have tried EaseUS recovery program and it has found my files (thank heaven!) but it asks to pay to recover these files.

After looking through and through, I've found testdisk, and followed the instructions to get an image copy of my hard drive. It had a similar size, which I believe is my files!

Buut this is the problem. It's compressed as a .dd file, and after a little research it seems to be an old UNIX compression file.

Is there any way to open this file to get my lovely stuff back?
An image copy (what you did with testdisk) is a block-level clone of your drive, not a file copy. it includes the directory, which does not include any of your files.

EaseUS, Data Rescue and similar programs can usually recover files from a formatted drive. Yes, they cost money so get out your credit card. Some have a preview mode that can recover a small number of files per scan, basically to prove it's worth investing in.

EaseUS costs $90, you apparently don't think your data is worth that much. Decent external drives cost about $200, a backup would have eliminated the headache you are going through. And there's more to come, as recovered files typically don't have the original filenames.

Also note that if you are talking about the disk drive in the computer you are currently using, the chances of recovering anything go down every minute you continue to use the computer.