I had seen lots of post detailing how to solve the problem of installing this software. Especially the part where it cannot find the WHS. I have a totally unorthodox way to do it, yeet it works for me.
First do make sure you can ping you WHS, otherwise, it definitely a network problem and not related to the software for you.
When you get to the part it say unknown error occurs, cannot find WHS etc, call up your Task Manager. Look for a few msiexec.exe file under Processes. Make sure you are not installing anything else at this same time. Kill them. If you are lucky, kill one and the rest falls.
Now, under the Applications tab, kill the Windows Home Server Connector software. It may ask you to Exit or something, do that will do as well.
What actually happens? IF you did not kill msiexec.exe, it will remove the software (rollback) when you exit the connector installation. But since its dead, the software stay. If you are lucky, it already running with a green icon on tray now when you exit. Totally working. If not just start it from Start Menu.
My conclusion is that somehow the detection during the installation is kinda screwed up. It works for many PC I tried. It justed work, even though the installation say it can't find the server. Hopes this helps.