LuckMC11, are you talking about Painkiller or games in general? For Painkiller the answer was provided about four posts earlier.
Open the config.ini file using WordPad. The default file location is here: C:Program FilesDreamCatcherPainkillerBin. Change "Cfg.FOV = 95" to "Cfg.FOV = 111.002536". Click File>Save. Close WordPad. Start Painkiller. If you already have 1280 x 720 available as an option for your desktop (i.e. it is a valid resolution choice for your video card) then 1280 x 720 should be a resolution choice in game for Painkiller. Choose that and frag away! (Other games, such as UT2004 or Doom 3 require .cfg or .ini file entries for your desired resolution, but not Painkiller.)