Why I can't play worms from IP 93.125.xx.xx?

What is the exact nature of your problem?

When I use another provider it's all ok, and when 93.125.xx.xx I can't connect to wormnet

See if you can connect to the WormNET IRC server. Do the following:
Open a command prompt (Start -> Programs -> Accessories -> Command Prompt) and type:
telnet wormnet1.team17.com 6667
You should either get a blank screen or error message.
If you get a blank screen, that's not the problem (your IRC port isn't blocked). If you get an error message, then something is blocking it, for example a software firewall or your ISP.

I can't do that - it says:'telnet' is not recognized as an internal or external command,
operable program or batch file.

I can play WA online, though...

I assume you're either using a 64-bit version of Windows XP or Windows Server 2003, or you don't have the Telnet client installed. Both of these are fairly non-standard configurations.

Oh, yeah, you're right... I have a 'slim' install of XP which comes with nothing, pretty much.

My bad - carry on!

When I use telnet wormnet1.team17.com 6667 from 93.125.xxx.xxx it did work. But when 10.128.xxx.xxx its ok.

Sor for my English.

What do you mean by "it did work" and "its ok"?

I think he means it didn't work from 93.125.x.x...

Yes. Wormnet banned that ip?

Could you be more specific? What error did you get, if any?