Ok, you need Image tool which is in the fsx sdk. Its located in the Environment Kit/Terrain SDK folder. Next is to open notepad
and add this line:
imagetool -nobeep -nomip -dxt5 -dds -nodither *
Now save the file (save as) and name it (compiler.bat). Create a new folder any where on your computer and name it something
you'll remember. Place Image Tool and the batch file into the folder. Now to convert the bmp files, you can just move them into
the folder or copy/paste (your choice). Then double click on the batch file and it will convert the files from bmp to dds.
Once its done you will have the bmp's and the newly created dds files in the folder, just delete the bmp's and move the dds files
into the texture folder of said paint.
Joe