是否有任何唯一识别设备的机制(即使是匿名的)？

要清楚，通过“设备”我的意思是电脑/平板电脑。

Windows 8.x

07000

string HardwareId()
{
    var token = Windows.System.Profile.HardwareIdentification.GetPackageSpecificToken(null);
    var hardwareId = token.Id;
    var dataReader = Windows.Storage.Streams.DataReader.FromBuffer(hardwareId);
    var bytes = new byte[hardwareId.Length];
    dataReader.ReadBytes(bytes);
    return BitConverter.ToString(bytes);
}

Windows 10

You must add the Mobile and/or Desktop extension SDK.

string HardwareId()
{
    var token = HardwareIdentification.GetPackageSpecificToken(null);
    var hardwareId = token.Id;
    var dataReader = Windows.Storage.Streams.DataReader.FromBuffer(hardwareId);
    var bytes = new byte[hardwareId.Length];
    dataReader.ReadBytes(bytes);
    return BitConverter.ToString(bytes);
}

Windows 8 RTM中刚刚添加了这样的功能：

Windows.System.Profile.HardwareIdentification.GetPackageSpecificToken(null)