Q: The Windows service seems to be running, but when I open the GUI, I get an error about ports being in use, and to remove and reinstall the service.

A: First, try removing the service and reinstalling. If that doesn't fix things, this is how you can reset everything.

Open the crush GUI. Go to manage servers. Remove all items in there, and click OK.

If you don't have any server items listening on "lookup" or listening on "127.0.0.1", then open your server prefs, add a new server item on port 8080, sharing users and groups from another server item.

Set its IP to be "127.0.0.1" instead of "lookup".

Click OK.

Now install the service again.

Q: Is it possible to run the server on ports below 1024 and not run as root on a Linux/Unix system?

A: Yes. Use the built in firewall to setup a port rewrite.

sudo iptables -t nat -A PREROUTING -p tcp -m tcp --dport 21 -j REDIRECT --to-ports 2121

Then just run CrushFTP on port 2121 instead.