Hi All,
I had been having trouble getting the tpPLC utility to see my PA-9020P adapters. They were working fine; I could see all of my local network, and access the internet. The tpPLC utility just wouldn't see them. I scoured the forum and saw lots of people with similar sounding issues, but no real help given beyond things that seemed basic.
I eventually tried installing the utility onto another desktop computer, but still no result.
I then tried on a wirelessly connected laptop; and bingo I could see the adapters : )

I still wanted to try get this working on my main desktop. I tried playing around with firewall settings, but still no luck.

I installed the utility onto another wireless laptop, and that worked. Hmmm.
Double checked the documentation, and read about the utility requiring  WinPcap (version 4.1.2 or higher ). Thought this may be the issue, so downloaded a version of WinPcap, and tried to install this on my desktop; only for the installer to say that I already had a higher version installed.
Then I thought I try installing the utility on a virtual machine that runs on my desktop. Started by installing WinPcap 4.1.3; then installing the tpPLC utility. Installation seemed to go fine. Running the utility, I got a message from Firewall about allowing an app to run. Said OK to this, and BINGO again. The utility ran fine and detected my adapters.

My conclusion is that the tpPLC utility is very fussy about which version of WinPcap is in use. The utility won't run on my main desktop, which has a later version of WinPcap, and I don't want to uninstall it. I assume that the utility install saw that I already had a higher version of WinPcap installed, and just went straight through; but the utility wouldn't work with it!