like this maxscript (DotNetClass "System.Environment").SetEnvironmentVariable "Path" "d:\\"can set EnvironmentVariable,but do not modif the systemonly set for max process
http://msdn.microsoft.com/en-us/library/z46c489x.aspx
You are using the same .NET method from MaxScript :)
Marsel Khadiyev (Software Developer, EPHERE Inc.)