If you have a HDD whose File System is labeled "RAW", the MOST likely reason is that some bits of data in the Partition Table or, more likely, the directory and sector allocation systems, is corrupted. The files themselves are all OK, just not accessible.
Search the net for how to recover files from a RAW File System. You probably will find tools that can recover all the data and allow you to copy it to a good other HDD. Of course, that means you need a second drive with space to accept all those copies. Once you've got all that backed up you can basically wipe the original HDD clean and re-do the Partition / Format / OS Install process, then restore all the files.
I have not done this process, but what I read is that there is no simple way to just "tweak" it or convert a corrupted system that is RAW back into a good drive with a small adjustment.