The agents probably won’t help with obsolete software which PSE11 is. You get to them by going to the Contact Us page and specifying what product and what type of problem and then clicking Still Need Help at which point you should see a Chat button and a phone number, as long as Adobe provides those services for what you’ve specified as your product and problem.
What version do you see when you do Help / About Plug-ins / Camera Raw in the PSE11 Editor? Is it possible that you have the right version of ACR but the files are corrupted so it looks like you don’t? Using obsolete Nikon software can corrupt NEFs from newer cameras, but you can fix that corruption with a utility from here:
http://owl.phy.queensu.ca/~phil/exiftool/fix_corrupted_nef.html
There should be a way to hand install the Camera Raw.8bi file using a procedure similar to the following adjusting the names of the files and locations for PSE11 and ACR 7.4. Without knowing what your EXE is, it’s hard to know if the procedure is reasonably compatible or not:
https://forums.adobe.com/message/5959479#5959479
Here are direct download links to the ACR 7.4 setup.zip needed in the preceding instructions: