If I am opening a command prompt in Windows XP and type - set FOOBAR=D:\test\project, then the environment variable FOOBAR is set for this command prompt session to the new value. But it is not changed for the global environment of the whole machine? To change it for the global machine I have always to go to, Control Panel > System > Advanced tab > Environment Variable Button and then change it manually there. Can anyone tell me a way to change the global env varible values from comman line? Thanks.