I have PSE 9. Recently purchased a new camera (Nikon D7100). Files shot in raw/nef do not open in Camera Raw, nor can I edit or convert via the PSE 9 workspace. I tried to upgrade my Camera Raw version but I'm not sure if I was successful.
Moved to Camera Raw. If this area does not fit your problem please let us know. You are in the Lounge and there is no technical support here.
Your software is too old. The D7100 was first supported with Camera Raw (ACR) plug-in 7.4 and that was first available as an update for PSE11.
PSE14 is the current version although I’d expect it to be replaced by PSE15 within a few weeks.
So you can either update your PSE to a newer version, or use DNG Converter 7.4 or newer (current is 9.6.1) to create DNGs from your NEFs, one folder at a time, and those DNGs but not the NEFs will open in your older software.
You can get the DNG Converter from here: http://www.adobe.com/downloads/updates/
You can get a PSE trial that you can later purchase from here: http://www.adobe.com/downloads.html