There are MANY, many people who are using Windows 8 Consumer Preview as their primary OS / Operating System now.
This can range from people who are tired of Windows XP, hate Windows Vista, or simply wanted a change from Windows 7.
As such, you may not have two partitions created for a dual boot configuration (or if you do, you don't want to switch off of Windows 8).
So you may have noticed something annoying -- Borderlands 2 Won't Open on Windows 8!
It simply won't launch. You double click the EXE or try the launcher and nothing happens.
There's a Windows 8 Fix for it that's out, but that only works for version 1.0.0 and if you patch your game and get the new DLC's, then it just won't open and won't work. I will first address how to fix this problem on Windows 7 (32 bit and 64 bit).
Borderlands 2 - Fix Windows 7
This solution is incredibly easy.
1) Install STEAM
Done! Told you it was easy! Still not working? You may need to create a registry file. Open a notepad document (START -> RUN -- NOTEPAD) and paste the following in IF YOU HAVE 32bit / x86 copy of Windows 7:
If you have 64-bit / x64 Windows 7, then paste the following instead:
"InstallPath"="C:\\Program Files (x86)\\Steam"
Save the file as "whatever.reg" and then run it. Your game should now work.
Run Borderlands 2 - Windows 8
Running this game on Windows 8 is a whole different problem. Something about the game just disagrees with the OS it seems.
If you haven't patched your game yet or got the new DLC's, then there is a Borderlands 2 Windows 8 fix / patch for it that you can get. This patch has not been made for the newest version of Borderlands 2 though, so you won't be able to play with the Mechromancer class or play the DLCs.
There's a hack / mod you can do (if you want to call it that)...But it isn't the most pretty of things in the world.
Navigate to your Borderlands 2 EXE (not the launcher) and Right Click it -> Propreties -- Set the COMPATIBILITY to Windows 98 / ME (setting it to Windows 95 should work too)
This will allow the game to run, but it won't run without lagging. Good news though -- there's ANOTHER trick to help take care of the lag that is caused by this.
With Borderlands 2 opened, launch Task Manager (CTRL+ALT+DEL) and locate Borderlands 2 under the "details" tab. Select "Set Affinity" and check all the boxes so that all the cores you have in your multicore processor / CPU are enabled. It'll be much faster this way than before, but you WILL still experience lag (just not as much).
Hopefully that took care of your Borderlands 2 launch failure!
Note that apparently there is a copy of the game released by Skidrow or Blackbox or something that and has the same problem. I recommend buying the game though -- through Steam or a CD / DVD copy -- as this game is worth buying and you should support the developers!
Still not working? Check out FIX: Borderlands Fails to Launch - Nothing Happens for additional help and solutions.