The new downloadable content (DLC) for Left 4 Dead, Crash Course, is now available for both Xbox 360 and PC users, so there’s just one thing left to do: play it!

Well, if you’re a PC player, you’ll also need to patch Left 4 Dead to fix some issues introduced by Crash Course. Details on that follow below.

But if you are an avid Left 4 Dead player, and you haven’t yet released 560 of your MS Points on Xbox LIVE Marketplace to buy the DLC, or downloaded it through Steam (for free), here’s a quick gameplay video from the new content to entice you into doing so:

For PC players, you’ll need to patch Left 4 Dead to append some errors that Crash Course has introduced - to get the patch, restart the Steam Client and execute Left 4 Dead. Issues fixed with the patch include:

• Made the variable “mp_gamemode” available again. Note that you can also load maps directly with different game modes by specifying it in the map command. For example, “map l4d_garage01_alleys versus” will set mp_gamemode versus for you automatically and load the first map of Crash Course

• Added “mm_dedicated_force_servers” to allow specification of a list of dedicated server addresses manually used for searching (ms_force_dedicated_server is depreciated)

• Updated shared libraries and DLLs preventing dedicated servers listing correctly, appearing on Steam groups, and being found via sv_search_key