Force Field is incompatible with SPTD. Any software relying on SPTD, like Alcohol 120% in my case, will not work.
For the moment, when I want to use the Virtual Drive of Alcohol 120%, I have to disable ForceField (in Browser Security, choose off ) and then stop the Forcefield IswSvc service (right click Computer in Windows Start Menu, choose Manage, in Computer Management choose Services under Services and Applications, click on the ForceField ISWSVC service and choose STOP service).
Alcohol Virtual drives now works correctly. Restarting the service and reactivating ForceField disable the Virtual drives.
Let's hope next version of Force Field will correct this.