Should I remove my old HDD?

[saffron3d]

I originally had a 320 GB HDD but I recently bought a 2TB HDD and reinstalled Windows 10 to it, while still leaving the old 320 GB HDD to get some more space. I downloaded CrystalDiskInfo to check my HDD status and it says it's in a critical state. Here's a screenshot:

 

[elbert]

You should retest the drive with seatools. Do a smart, generic, and self test. Long as it passes those it should be fine for starage.
http://www.seagate.com/support/downloads/seatools/

 

[saffron3d]

You should retest the drive with seatools. Do a smart, generic, and self test. Long as it passes those it should be fine for starage.
http://www.seagate.com/support/downloads/seatools/

It failed the S.M.A.R.T and the self test but passed the short generic test.

 

[Solandri]

Spin retry count is usually indicative of an impending critical failure. The drive is having problems spinning up.

However, each manufacturer codes their SMART codes differently, so follow elbert's advice and check with SeaTools first. If it confirms the critical spin retry count, then yeah you should trash this drive. Either its bearings are starting to seize up, or the motor is dying.

 

[mjslakeridge]

Was the old HDD connected to the system when you did a clean install of Windows to the new HDD? If so, and if the old drive fails or you take it out or reformat it, Windows MAY not boot, as the Windows install could have written some boot files to the old HDD. You may want to test that out now by powering down the computer, disconnecting the old HDD's SATA cable, and then power the computer back on. If it boots into Windows, you are fine, but if it doesn't, at least you will now rather than later.

And doing what elbert suggested makes sense, but with any storage device, have anything important backed up is a good practice.

 

[elbert]

You should retest the drive with seatools. Do a smart, generic, and self test. Long as it passes those it should be fine for starage.
http://www.seagate.com/support/downloads/seatools/

It failed the S.M.A.R.T and the self test but passed the short generic test.

I wouldn't suggest using it in the system. Could be used as a removed redundant backup. Set it on a shelf and hope it still works if you need to pull any data off it.