On my Windows 2000 OS, I click Start > Settings > Control Panel > Regional Options and it is under the Numbers tab, Decimal Symbol.

Lou

I use XP and I do not recall having to do anything special to my system before I used gmax. Nor do I recall any mention of system settings in gmax. The only thing I recall is it telling you to change the setting in GMAX it self. Make sure every thing is in  the correct place Gmax should not be installed inside of FS but in its own directory and the FS2004 game pack needs to be in Gmax I can not rember if it puts it there automatically or not.
When I get home I will look to see exactaully what is where you might not have something in the correct folder 8)

I am doing my best to help you if you will send me a private message with your email address I will send you the tutorial for the house. It will explain every thing step by step.
The game pack folder should be inside of gmax and the FS2004 folder is inside of the gamepack folder PLEASE THIS IS NOT THE MAIN FS2004 FOLDER but the SDK folder so please do not move your main fs2004 folder
If you do not know how to send a Private message just click on the name of the person you want to send a pm to and select the send private message. When you logon it will tell you if anyone has sent you a pm if you notiuce I sent you one. 8)