If You want to login to server, You'll need Lineage II Interlude cliend and this patch:
L2Java.exe (11MB) [zippyshare.com]
Mirror 2 [mediafire.com]
Mirror 3 [local]
After running it shortcut will apear on Your desktop. Thats it.
P.S. If you don't have Lineage2 Interlude client, you can download it with installed our server patch using this torrent file: L2Java_client.torrent