Ok my friend, do as below, and it also works on RC2 aswell.. Cheers
How To Install Alcohol 120% on to Vista RC1/RC2 By (YaN, Stoke, UK) October 21 2006
Rename the Alcohol installation exe to Install_A.exe and double click, this will now install. (Ignore any errors)
Now Rename the Main alcohol exe in the Alcohol folder to MAIN_A.EXE
(Not forgetting to also change the Shortcut properties on your desktop to point to the new name)
Now run the compatibility wizard and select the MAIN_A.EXE and set it to run as
Windows 2000 and run as Administrator.
When the main alcohol window comes up, you will now be able to setup the Virtual drives with no errors.