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Windows Mail is the desktop email program replacement for Outlook Express that is included in Windows Vista.
Windows Mail improves slightly on Outlook Express by keeping messages in separate files. That can be used to resolve issues with some messages.
Microsoft has created a lot of confusion with how it names its mail products. Add the transition from MSN to Windows Live branding and it gets worse.
Outlook Express, Windows Mail and Windows Live Mail store your email in a user-specific location that can be difficult to locate. We'll find it.
Your email and contact information should be backed up as part of your overall backup strategy. Or you may want to export them.