Well, I've tried installing alcohol 120% via:

ECHO.
ECHO Installing Alcohol 120
ECHO Please wait...
start /wait %systemdrive%\Install\alcohol120\Alcohol120_trial_1_9_2_1705.exe /qn

However, no matter what, i get a warning screen to choose yes or no to accept the software install. I thought /qn supressed the UI.

Thoughts?

Not sure exactly how I managed to generate a msi file for this install, but I did. The following seemed to work and suppress any user interaction:

start /wait %systemdrive%\Install\alcohol120\trial_setup.msi /qb Reboot=Suppress

How can I find out other switches such as reboot=supress? I mean to say, I understand some switches are within the scope of windows installer 3.0, but what scope does the reboot=supress exist? I can't figure out why this works.

Two things:

1) For the reboot suppression you should use REBOOT=ReallySuppress. That's direct from the Alcohol Soft team

2) A nifty little trick I learned is how to change the driver names during a silent install (to avoid blacklisting).

/qn REBOOT=ReallySuppress DRIVER0=xxxxbus DRIVER1=xxxxscsi

Hope this helps.

Can you please explain what you mean by blacklisting?

Blacklisting is when certain copy protection companies (like SecuROM and StarForce for example) try to prevent a game from running if they detect the presence of a program like Alcohol. One of the ways they detect Alcohol is through the driver names. By changing the names of the drivers that Alcohol uses, you've removed one avenue of detection for the copy protection makers. Just replace the xxxx with whatever you want.

You might also be interested to know that you can edit the comments in the SFX RAR file itself so it automatically applies those commands. Just open the package in WinRar, press ALT+I, click the Comment tab and modify the Setup= line with the switches above. Keep in mind that you MUST reboot after installation before running Alcohol for the first time. If you do not, Alcohol will not work properly.