Well first of all you were stupid enough to open it with paint so that kinda messed up the file and because your a newb i bet you dident make a backup, _T_ is for texture _M_ is for model, Were you trying to cross modd or just change the color of the gun? If so you need to change file extentions with photoshop and go through the whole spadutle of setting up a new computer with that... Otherwise u fked up that file and might have to reinstall.. Great going..