Hard Drive suddenly became unresponsive, recovered on reboot. What to do next?

If the disk only crashed once and now everything is OK, then this event was maybe exceptional.

My own guess is that the hardware overheated because you were using a lot the GPU and/or the CPU.

What you can do to check the problem :

• Look for a useful error or warning in the Event Viewer
• Install a product that can show the disk S.M.A.R.T. data and tell you if there is a problem (example Speccy).
• Install a temperature-monitoring product such as Speedfan which can be configured to display the current temperatures in the taskbar for easy monitoring.

If heating up is the problem, you may :

• Verify that the game uses the video GPU and not the CPU
• Clean up all airways
• If a laptop, place it at an angle, so the air can pass below it, or buy a cooling pad
• Renew the CPU thermal paste and heat sink (better done by a professional)
• Replace the CPU heat sink and fan with a better one (also better done by a professional)

The command you ran: chkdsk d: /f doesn’t do any checking of the drive surface.

The proper command would be: chkdsk d: /r this will perform a full surface scan. If bad blocks are discovered the drive is failing.

You can also use SeaTools and do a long test. Short tests do not check the drive surface.

Chances are the drive is failing. I’m assuming it’s a Seagate if you are using SeaTools. Seagates are not only notoriously low quality drives, they do exactly what you described when they start getting bad sectors. Instead of recovering, they shut down completely until power cycled.

Skirting the line of personal opinion here, it’s not really a loss to get rid of it now before it inevitably dies. Stay away from that brand.

Move on

In your question you seem to ask which things you 'can' do, but in the title you ask what you should do.

To list the key points:

• You have a backup
• The problem only occurred once
• You did some checks, which came out clean

At this point it simply not time efficient to keep digging deeper. (Unless you enjoy it). If the problem persists, you can always decide to go deeper in your search, or replace the drive.

Of course some generic maintenance (e.g. cleaning the fans) can never hurt, but don't spend too much time on it.