You really should try it out once before asking.

(saves time on waiting for answer)
You wanted some plugin to make WMP minimise to tray, and that's what the above does. Minimise to system-tray (the words) *IMPLIES* that there is no tab left on the taskbar. Please note, that the plugin above, is only for a WinXP with WMP9 installed. (I'm not sure if it will work with WS2k3 - but you can try it and see. In any case, you should not look for entertainment on a server

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If what you want is to minimise to taskbar with controls on the taskbar, then you don't need to add anything else - WMP9 and 10 has that function by itself.