I downloaded the FSX Boeing 737-800 Multi Textures Package (Updated) and when  i installed it i forgot to make a back up cfg file and now none of the aircraft come. So what should i do.

The only thing could think of is if someone just sent an copy of the origional deluxe edition cfg file to me at pgd6693@hotmail.co.uk and i forget about the other textures

If you followed the author's instructions to delete the existing Aircraft.cfg file look in your Recycle Bin. Providing you didn't empty it the file should be in there. Right-click on the file & select the Restore option.

If that didn't work a full Aircraft.cfg is included with the Multi Textures Package. It looks a little weird to say the least but should work with no problems. The easiest way to install this package would be to paste the included 6 x Texture folders + 1 x Aircraft.cfg file into the default B737_800 folder. Overwrite files/folders when prompted.

I would send you the original CFG file but I only have the FSX Demo. It should be possible to retrieve it from the DVD but I have no idea where it's located. If you don't have many addons installed the easiest way to fix this would be to use the FSX 'Repair' function to restore the default files.