Confused, I cannot edit my post or what. :-D
I overestimated the difficulty.
0)Just copy everything but the virtual disk into the folder 'backup'
, then when failing at the game
1) 'unplug the VM'
2) copy&overwrite from the backup
3) start the VM as normal
better than 2) : (it does the copying while you are playing)
preparation:
1)
copy C:\VM-folder\backup C:\VM-folder\backup-copy
2)
create a .bat file (google for tutorial) with this content:
move /y C:\VM-folder\backup-copy\* C:\VM-folder
del C:\VM-folder\backup-copy\
copy C:\VM-folder\backup C:\VM-folder\backup-copy
double-click the script and then start the vm as normal.
RamDisk works by setting the working directory to the ramdisk location and copying all the vm files except for the virtual hard drives into that.