This morning, I noticed that the “Sharing” tab was missing from my folder “Properties” windows. I have no idea how long this has been the case, but it’s something that I need to be available when I need it.
There was also no “Share With” option on the right-click context menu for folders.
Searching the Internet lead to a lot of suggestions that did nothing to fix my issue, but this thread provided the critical hint. Someone else with the same problem figured out that ntshrui.dll is the library that provides the sharing functionality, and somehow it was not being called. The solution was to look in the registry of a fresh, working Windows 7 install for references to this library and copy them over to the install with the missing “Sharing” tab.
Although he reports success, he doesn’t give the registry entries. So, I booted up my Windows 7 VM, looked for entries that seem to tie ntshrui.dll to sharing functionality, and exported them all. I imported the registry file on my main Windows install, which was having the problem. After logging off and logging back on, I found the “Sharing” tab to be back.
Here is the registry file that I ended up with. If you have this problem, try importing the file (don’t worry if you get an error that not all entries could be written), and then log off and on again. It might work, but it’s possible that there are other things that could cause this as well.