gzipped files?

[Ringo]

I've used the serial/slave cable to download the trackxx.xxx.gz files in the gzipped format, it's recommended that i use the eo.exe program to unzip the .gz to .iso.
...problem is the program is in japanese, how are you meant to know what to select/do using this program?

Is there a program that'll do the same that's in English?