Help please...

Hi there,
I am new to the forum and I was hoping someone here could help me out with a slight problem I am having.
I recently downloaded a registry cleaner and accidentally cleaned out my entire registry resulting in me having to backup my entire hard drive of movies, photos and music and doing a clean install on Windows 7 64bit.
Once it was all up and running I moved all my files back to my computer and didn't notice until a few days later that 80% of my jpg images were corrupt and wouldn't open and the same goes with most of my movies being avi files.
The error is saying something about frame headers or something along those lines.
I have tried every piece of software I can think of to try opening avi's and jpg's but to no avail.
I also have tried putting a few files on my partners laptop but also to no avail.
I would really appreciate any help I can get.

Thank you for the fast response. In response to your questions, the hard disk was formatted before re-installation of Windows. I do not mind paying for software that will work as all photos of family etc are on here and very important to me.

Looks like the files are corrupted. Open one of the bad files in a hex editor or Notepad and see what the first 128 bytes look like.

The first bytes in a JPG/JPEG should be:
(hex) FF D8 FF ?? 00 01 4A 46 49 46, or
(ASCII) ÿØÿ???JFIF

You can compare with a good file.

You can try some file recovery program but afaik, if the concerned app cannot read the file, recovery is very difficult.

I am in the process of doing a chkdisk at the moment but as soon as that is complete I will give some software a try and if that doesn't work I will have to explain to my wife that it wasn't my fault.
Thanks everyone.