Big JOIN button on the top right?
Oh and i forgot to mention, you need to update your STEAM.
Just launch STEAM, go to File > Settings > Beta Participation and join the Steam Community beta.
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-------------------------------- Computer Specs ----------------------------------
Intel Pentium IV Prescott 3.0 HT → 4x 512MB DDR-DIMM → ASUS GF 6800 GT
Sound Blaster X-Fi → 2x Maxtor 80 GB (RAID 0)
Hitachi 19'' Monitor → Cambridge Soundworks Desktop Theater
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