You can run the command: photorec (part of testdisk package), from a live CD to recover many common file types (extensions). Just have another large drive to send the data to as it will recover lots.
You do not want to write to the drive you are recovering from.

Generally, the operating system is installed first and it's files are generally towards the beginning of the drive. It don't matter how many installations you've done overtop of Windows, most operating system files will not be written overtop the area of the drive where personal data is written. And it don't matter how many times the drive has been formatted as data carvers like foremost and photorec look for headers and footers of the file types you specify it to look for.
If you haven't written too much new personal data since you learned this lesson, you may still be able to recover lots with a simple command.