Well to repair the installation you want to go to start, all programs, eagle dynamics, dcs world open alpha then repair dcs world. If that doesn't work for you - which it didn't for me - try going to users, >your username<, saved games, and then find the folder for DCS World open alpha. This will contain any changes to settings etc you made to it whenever it was open. Delete the folder completely, and then when you start up again it will create a new fresh folder which will hopefully solve any of your issues. Unfortunately after I managed this my graphics card packed up so now I've got to wait till christmas to play... Good luck!