@mitu The problem I was having with Win32DiskImager was getting an error dialog box when trying to open the SD card device. It was a "cannot lock volume" error.
Turns out this is a big problem with Windows (10 in my case). Some applications (typically music players or photo catalogers) traverse the file system looking for things and can have things open on your "boot" drive letter so you can't use it.
I was finally able to get it to work using a fresh laptop machine. So if you have this problem you might be able to find out who has files open on your SD card using Microsoft's "process explorer" program and close that program or be forced to another Windows instance.
I'm doing testing with my "dd" idea now that I have media I can experiment with.