How do you tell if i have Windows Vista?
When you boot up just watch the screen and if it says 'Windows Vista' anywhere on it, then your operating system is Vista.
If your computer had Windows XP on it and you upgraded to Vista, I heard you could call Microsoft and tell them how displeased you were with Vista and wish to downgrade back to XP. They will then deactivate your Vista Product Key and give you a XP product key, you will also have to have a Windows XP cd.
System requirements for Windows Movie Maker v2.1 can be found at this URL: http://www.microsoft.com/windowsxp/downloads/updates/moviemaker2.msp ___________________________________________ System requirements for Windows Movie Maker v2.6: Supported Operating Systems: Windows Vista; Windows Vista Business; Windows Vista Enterprise; Windows Vista Home Basic; Windows Vista Home Premium; Windows Vista Starter; Windows Vista Ultimate Movie Maker v2.6 requires a version of Microsoft Windows Vista that has the Vista version of Movie Maker already installed.