when I create one virtual drive, after reboots additional virtual drives are being added automatically without my intention, so I start with e.g. drive F: and after several reboots DT adds addl drive such as G: H: I: J: K: and so on.

So I need to delete all drives and without any drive, no drives are beeing added automatically.

I work with Windows 8.1 not in Admin mode but in standard user mode.