You do not need to ever even load the CD-ROM into a computer, let alone install Silkypix.
Silkypix is a raw developer (also called a raw converter). "Raw" describes a family of file formats for encoding digital camera's sensor information. Every mfr. has its own proprietary raw file format (some have more than one). Raw developers take the data from these raw files and convert them to a displayable image format.
You can use any raw developer which can read your camera's raw files. Almost all -- perhaps even all -- raw developers can read the raw files from your GH1 right out of the camera. That includes Aperture, Lightroom, Capture One, and others (inc., of course, Silkypix).
Silkypix is usable, and comes with your camera. If you have and/or are going to use Aperture there is no reason to even install it. Aperture includes an excellent raw developer.
Good luck.