Is the laptop still seeing the Kobo as a drive?
Does Calibre there see it?
Unfortunately, if one Windows install DOES see it and another does not, it leads me to think that the Windows install on the one machine is causing problems
Sorry; I'm not sure what to suggest beyond this.
calibre / Kobo Desktop / ADE / explorer won't see the Touch until Windows recognizes it as a USB storage device and assign a drive letter to it.
Hmm... Do you see anything if you go into Control Panel | Administrative Tools | Computer Management and look at the Storage | Disk Management area (with the Kobo plugged in)?