Dear friend, I have 7zip file, Extract it and compress it again with 7zip GUI.I choose ULTRA \ LZMA \ 64 \ 64 \ solid option in 7zip GUI.after compression I compare it with original version.my 7zip compression ratio is about 95% but in original version is about 82%. I see property of original 7zip.the method in original version was "LZMA BCJ2" and "solid +" and "Blocks 2" but in mine version it is "LZMA" and "solid -" and "blocks 1" so my question is how and with which switch i can change my compression method?i read help of 7zip but it seems that switches for bcj2 dont work in GUI.