Where is Photoshop getting color profiles? Not from the Windows color profiles folder.

I had the same problem, in Windows 10 using Photoshop CS6, and solved it.

The folder C:\Windows\System32\spool\drivers\color had files AdobeRGB.icc and USSheetfedUncoated.icc.  They showed in Color Management under All Profiles as Adobe RGB (1998) and U.S. Sheetfed Uncoated V2. But neither one was in Photoshop Print Settings dialog Printer Profile pulldown when Photoship Manages Colors was selected.

I got them to appear, at the top under my printer's Epson IJ Printer 07 profile, above the horizontal line in the list. To do that, I went to the Devices tab of Color Management, selected the printer under Device:, then Add and selected the profile.

It worked right away with U.S. Sheetfed Uncoated v2, but I had to fiddle around with Adobe RGB (1998). It was on the Devices tab of Color Management just like the U.S. Sheetfed Uncoated v2, but not in Photoshop's pulldown. I exited and restarted Photoshop, and that might have done it. And in Color Management I selected Manual Profile selection and set Adobe RGB (1998) as default profile, and that might have done it. In any event, they are both now in the Photoshop pulldown, and Adobe RGB (1998) is the default when Printer Manages Colors is selected.

This page lists the location of the color profiles used by Adobe:

https://helpx.adobe.com/photoshop/using/working-with-color-profiles.html

Scroll down to "Install a color profile" for the location.