(Note: If you have not donated to the mod or contributed in some other way, sending in your Steam ID will achieve no result).

Firstly, if you haven't updated to the latest version of Half-Life (i.e. Steam), you'll need to do so. A number of installation options are available from Valve's Steam site. If you have any other problems, try the Steam Support System or Steam Forums.

Now presuming that you have Steam installed and Half-Life is fully updated and working, this is what you need to do to find out what your Steam ID is:

1:  Load Steam

2:  Load Half-Life (or Sven Co-op)

3:  Click "Find Servers"

4:  Join a server. It doesn't matter if the server has other players on it or not.

(Note: You cannot check your Steam ID on your own server, for some reason)

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5:  Bring up the console by pressing the tilde key. Type status, then press Enter.

6:  Your STEAM ID should be displayed beside your name (STEAM_0:0:13131 in the example above).

Write it down, or copy and paste it out. You could take a screenshot if you wanted to be extra careful.

Alternately, the website https://steamid.io/ may be of use.

Finally, send me an e-mail with the subject "STEAM ID". Include your full Steam ID (e.g. STEAM_?:?:???? ), the e-mail address you used when donating, the name used when donating, and any other relevant information. I'll send back a confirmation e-mail as soon as I can manage. If you don't see a reply after ~48 hours, please check your spam folder.