Hi,
Thank you for your reply.
I already tried that, I will try it once more since I'm not exactly sure which one I downloaded so I'll give it a try with your link.
Worth noting here - there was no gnutella.net file in the WS folder in %APPDATA% to begin with.

That's odd and should not be the case. The file should be inside \AppData\Roaming\WireShare
Did you have your WireShare port forwarded previously? If yes, it might be worth checking it is still valid after you reinstalled Windows. There's a minute possibility some routers might be affected by the OS reinstall, though in theory this should not happen. One exception might be the local LAN ip when a static ip is set, as this setting might have been lost.

Edit: oops you said it was set up as UPnP, my mistake.