tsk tsk tsk... what a sad set of responses. These guys are correct in saying to use a compression utility rather than what comes with XP or none at all. The file type (.zip or .rar or whatever you want) does not matter AT ALL.

The amount of compression you get out of the file depends on 2 things: type of file you are compressing and the ammount of compression. programs like Winzip, WinACE and WinRAR allow you to choose the leve of compression, so the answer to that is easy, choose the highest compression level.

The file type however, is important. If you were to two of the same image files, one being a BMP and one being a JPG, you'd find that the BMP has a MUCH higher compression rate than the JPG (like 70-95% compressed compared to 0-10% compressed). This is because a JPEG or GIF are already compressed files. This goes for the same with Video files. MPEG, WMV, and other finalized movie content are precompressed, so recompression does not do any justice, where an AVI normally is not compressed, and can be further compressed, since the data is more raw (keep in mind that AVI's can also be precompressed). Hense recompressing a compressed file won't do you much good, so recompressing a zip file will do just about nothing.

As for compressing down to 10% of the original size, I doubt they are doing it without any loss of quality or Visual size...

I hoped this helped.