Display color profiles broken after upgrading to Windows 8.1

The problem turned out to be that the Windows 8.1 upgrade process turned off the system-wide "Use Windows display calibration" setting. I had that setting turned on in Windows 8 to make sure my color profiles would work.

For some reason the upgrade turned this setting off, and the fix was to turn it back on:

1. Open the Color Management control panel.
2. Go to the Advanced tab.
3. Click "Change system defaults..."
4. Go to the Advanced tab in the Color Management - System Defaults dialog.
5. Turn on "Use Windows display calibration" and click Close.
6. Now go back to the Devices tab, change profiles there and click "Set as Default Profile" as usual.

On one of the two machines I stumbled into this fix through a roundabout route: I went through the built-in Windows calibration ("Calibrate display" button in the advanced tab), and after doing that, all the profiles started working. But the actual fix was that the built-in calibration procedure also happened to turn on the systemwide Windows calibration setting. On the second machine I skipped the Windows calibration and just followed the procedure above and it worked.