Linux vs Windows file system

Hi All!

I have some troubles to get back some important data from my old HD. Namely, its power supply was damaged and I had no access to the files on it. I took it to the service and they promised they will get back the HD to life as soon as they find an identical HD from which they can remove the parts my HD needs. 5 months pause. After that, they called me and told me the HD is OK, they have formatted it and copied my files back.
Then I made a mistake and installed Linux Ubuntu 8.04 and now I can’t find any of my files in the system. I tried to install Windows but I can’t do it without formatting the HD and that will result my files will be lost AGAIN!
What should I do to save my files now? Any help is appreciated!

If you installed linux on it, you reformatted the drive and likely wrote over the data. If there was data worth several thousand USD, you might want to take it to a data recovery specialist. Otherwise, you are SOL at this point.