Data Recovery : The first steps
If you've accidentally deleted a file and have no backup, the best thing you can do is shut down the computer properly without any hesitation. Click the shutdown button and let the computer do its normal shutdown. Then call Computer CPR.
If you believe your hard drive has crashed, it's best to avoid any further restarting attempts because these may further damage the hard drive.
Just because a hard drive isn't properly reading some sectors, doesn't mean data can't be recovered. But the important thing here is a proper shutdown without any further hard drive activity.