about the commandline mode of disk2vhd

How to write parameter t, then i can use its volume shadow function?

Look this note, "-c" is to no use of the volume shadow copy.But,how to use?there is no words about it.I guess,don't write "-c",means to use this function?

But,no matter how to use these parameters,the following popup program window,that small “use volume shadow copy" box,is always not chosen...

So,please tell me,how to write the parameters,then I can use the "volume shadow copy" function to create the backup file?