Well,i know how to compress a file of course,but i don't know what programm to use to get the smallest compressed file size.

I've got WinRAR,WinZIP and 7Zip.
They are compressing pretty well,but i need even smaller files.
I wan't to compress a 267 MB file into a ~45 MB file.

I've heard about tools like "UHARC" and "KGB archiver".
Got them both but they are somehow not working.

Can someone help me?I need it to upload some files to MPGH.