Go to control panels/system/hardware/device manager, find under "SCSI and RAID controllers" the Alcohol SCSI controller from the previous version, and remove it.
All Alcohol drives will disappear. Normally this happens automatically when you uninstall alcohol, unless at the uninstallation time you still had some image mounted.
Also remove Plug and Play Bios Extension from System Devices. and if needed the Virtual Drive Drivers from the Windows/System32/Drivers Folder.