My menu works just fine, but after trying to start a quick game, the "Please wait... working" window pops up, and worms crashes back to desktop.

I followed the installation guide exactly on
http://www.nanacide.com/wahelp/installguide-original2.php

Also have a look at the FAQ section there.
www.nanacide.com/wahelp

R4. Why does WA quit after the title menu?
This is caused by "DirectVobSub" in the Nimo DivX Codec pack. Uninstall the Nimo DivX Codec pack and it should work. You can reinstall it and manually unselect "DirectVobSub" to get WA to work with Nimo installed.

This is the closest I found to my issue. Where would Nimo DivX be found? I can't find it on my computer.

Alternatively it might be something altogether.

Control Panel > Add or Remove Programs

It should be in there if you do indeed have it.

I don't think it's Nimo Divex. Any more suggestions?

On closer inspection, that particular FAQ isn't relevant to your problem anyway, since your game crashes after you try to start a game, rather than after the title menu.

The only thing I can think of is that you patched it when you shouldn't have, or you didn't update it. Try re-installing.

Yes. Follow patching instructions at www.nancide.com/wahelp

I also have this problem, does anyone know what to do... i cant play LAN with my friends.

Yes. Follow patching instructions at www.nancide.com/wahelp