Have you tried running your textures through Gimp 2 using the free plug-in called insane bump? Oh, yeah - Gimp 2 is also free. Then you can convert your necessary files provided you through Gimp 2 in Paint.net to .dds textures - which, by the way, is also free (don't let the name fool you - Paint.net is actually a stand alone paint program which installs worry free and cost free in your computer). I have been using these programs for years with no problems. So there you have it - two deliciously useful proggys along with one awesome and free plug-in that will take your textures to the next level!
All you need is love....so let me have your burger.