thx for the  hints
i use win7 ultimate
the thing is
1. after reinstalling Makemkv and first start, Makemkv finds the virtual disks (both Alc120 + virtual clone drive) 
2  after closing Makemkv and second/third ... start of Makemkv, the prog does 
not find the 2 disks again 
very strange 
 
cu Bernd