Recover lost files

[MMXMonster]

A friend has asked me if I could take a look at his once functioning computer. For some reason his drive now is labeled as RAW not FAT32 nor NTFS. It seems the drive got wiped but there is something still taking up space and was hoping a program may be able to recover the files or best case scenario find the windows folder and files and boot.
What could have caused such a thing and what program has the best success rate at retrieving the files?

 

[kenrivers]

Here are some possible software solutions:
http://www.easeus.com/datarecoverywizard/recover-raw-drive.htm
http://www.cgsecurity.org/wiki/TestDisk
http://www.****/
If the program runs a deep scan, highly suggested, it will take a while for the program to find recoverable files.
A possible reason for the drive to have become "RAW" is the Master Boot Record is corrupt.

 

[MMXMonster]

Best answer selected by MMXMonster.