Update
I've mentioned this in the comment already, but it's worth repeating here to avoid any misunderstanding: this issue is gone after numerous Windows updates. This means that unfortunately I won't be able to test/accept proposed solutions. Hopefully your comments will help someone else, though, so thank you for writing them!
Original issue
I've upgraded to Windows 10 Pro and have a strange issue with Windows Search: whenever a search result is a Control Panel item (e.g. "Administrative Tools", "Mouse", "Sound" etc.; and I'm talking about the old style Control Panel, not the new better looking Settings window) I can't open them with a click/enter! This issue also applies to a few other setting items not directly visible in the Control Panel (e.g. Disk Management settings such as "Create and format hard disk partitions").
Other search results are functioning just fine: I can open apps, files, Control Panel itself, settings exclusive to the new Settings window, e.g. "Pen and Touch" (it's a guess re exclusive, since when a setting item is available in both old Control Panel and new Settings, I can't open it), etc.
I can use the settings themselves just fine, but I have to first open the Control Panel itself, which is rather annoying.
SFC /SCANNOW
from an elevated command prompt? You might also try running cpl_file_assoc and then rebooting afterwards and then seeing if you still have the issue. As a last resort, you could try resetting Windows 10