判断Windows操作系统的版本

private void Form1_Load(object sender, EventArgs e)
{
    if (!IsWin7())
    {
        Application.Exit();
    }
}
bool IsWin7()
{
    return Environment.OSVersion.Version.Major ==  && Environment.OSVersion.Version.Minor == ;
}
bool IsWinVista()
{
    return Environment.OSVersion.Version.Major ==  && Environment.OSVersion.Version.Minor == ;
}

其它一些Windows系统：

Windows Server 2008 R2
Major=6
Minor=1

Windows Server 2008
Major=6
Minor=0

Windows Server 2003
Major=5
Minor=2

Windows XP
Major=5
Minor=1

Windows 2000
Major=5
Minor=0

Windows NT4
Major=4
Minor=0

Windows ME
Major=4
Minor=90

Windows 98
Major=4
Minor=10