THD, I've spent a few hours following your instructions. Thanks for posting them! Your instructions got me running.
My TLA715/7AA4 is running XP with version 5.1 application.
Following your advice, I installed TLA App 6.1.127.0 on my Windows 10 PC. I copied this newer /Firmware folder to the TLA715, after renaming the existing /Firmware folder on the '715 to "Firmware_5_1" to retain the original. After this swap, I updated the 7AA4 module to version 5.8.
I followed your advice, opening the Advanced Firewall in Windows 10 and allowing edge traversal and all private permissions for the TLA application, TekVISA, and tlnkmonsvc .exe's. It seems these three are all that were needed.
On the Windows 10 PC, in the newer TLA App, entered in the IP address I'd assigned to the TLA715. Like you said, automatic assignment did not work; the app would locate the TLA715 but not its modules. Static IP is necessary.
I found that running the TekVISA app and clicking "update" was a faster method to test the LAN connection while trying to make it work. When I got it right, the TekVISA will recognize the TLA715 and its 7AA4 module.
Thank you very much for your post! I am very happy running the TLA Application on Windows 10 on the same PC I am coding the FPGA

Another thread on this forum taught me how to unlock the 450MHz / 32MB capacity of the 7AA4 module. How awesome is that!
Thank you,
papafuse