What is this extension?!?

[foohoo]

My m8 just got the complete guide to linux and in it the free cd with "demo linuX" i didn't really care till i found he had the whole game of uplink with it. So i borrowed the cd and got the folder with all the files in for uplink and went to decompress them, but the extension was .gZ and i thought it was a gzip file but gzip doesn't recognise it and if i rename it to a .gz file it says the gzip is out of date but i had just installed the newest version with out a problem

can some help?

[slant6]

Is it possible the file is corrupted? Or possible that the wrong extension have been named to the file?

Try using the 'file' command if you have it installed. See what that comes up with.

Try 'man file' if you've never used the file command before.