I want to backup my FS2002 files by zipping them up. Is there a rule of thumb as to what size file I should expect after the zipping operation? Does it reduce files by 50% or 25% or is it a case by case issue? Thanks!!

It's a case by case issue....If you have a scenery file with few textures, you'll get a good compression rate. Same is true for an exe. (my landclass assistant updates usually have about a 5 to 1 compression ratio). But if you have scenery with a lot of textures, or an aircraft with a lot of textures, your compression ratio might not be as high. Or, if you have a package containing a lot of compressed format images (like jpg's), you'll get almost no compression, as the images are already highly compressed.My general experience with mixed use has been about a 5 to 1 compression ratio. You can learn more by looking at the "Zipdive" option in Avsim's library. The original file sizes show, and you can get an idea of how various types of packages do when zipped.Regards,-John

Thanks John!!