I’ve got an old HDD that recently stopped working properly—it’s not being recognized by my computer, and I’m worried the data might be lost. 
There are some important files on it that I’d really like to recover. Has anyone dealt with a corrupted hard drive before? Are there any tools or methods you’d recommend trying before going to a recovery service?
I’m open to any suggestions—free or paid. Thanks in advance for any help!
As far as i know recovery shops charges are very high. My friend got some important data from his corrupted hdd by paying a very high amount. They have softwares which can detect and recover data from it. They ll also ask you which data you want to recover. You may purchase some softwares to try but i m not sure which are working perfectly.
Is the drive not at all visible to the OS?
If you are on Windows:
Can you check Disk Management and if the drive is visible there?
Also, check device manager and see under disk drive there is a device with a yellow exclamation icon.
If the drive is somehow getting detected in any OS there are good chances of recovery. If no then only way is prof. recovery services.
Is there any error message (like not allocated) ?
A year ago, I opened the HDD and adjusted the platter head. It worked for a while, but then the issue returned. Is the HDD showing on disk management.
Use r-undelete or r-studio. Scan the disk whole image while you can and save it. Then you can use the image to recover files without connecting the hdd.
Some things just can’t be done with software
What confidence, opening hdd in a typical room/environment. 
We have India’s only certified Class 100 Clean Room lab
I haven’t cared about that disk, so I opened it, knowing things do go wrong, but somehow it worked.