TRY this method to bypass the following Error: "Unable to find Ubisoft Game Launcher, Please re-install Assassin's Creed II. Ubisoft Game Launcher: Error code 1."
This usually happens when the registry entry for the 'Ubisoft Game Launcher' is invalid. First try to Uninstall the Ubisoft Game Launcher, using the 'Add or remove programs/Programs & Features' tool in the control panel. Make sure any anti virus and firewall on your computer is first turned off. A full reinstall of the game should not be necessary, IMO, but if this problem persists, then you must do it.
First you can also close any unnecessary Startup programs/background tasks:
To do this click Start, then Run, then type MSCONFIG and click OK. From there click on the tab marked startup. For Windows XP users click the button marked as Disable All, then click Apply and Close. Windows 7/Vista will launch Microsoft's System Configuration Utility. Click on the Startup tab. This takes you to a page with a list of 'startup items'. Some startup programs are absolutely necessary, others are simply a waste of RAM. Disable only those programs that you recognize, and don't need to have running all the time. When in doubt, leave it on. Click on the OK button. A message will pop up telling you that you must restart your computer before these changes will take effect. Click on "Restart" and your computer will automatically reboot.
Also delete all Temporary files from your system:
From the Start menu, select RUN and type %TEMP% and click OK, this will bring up your Temp folder, Delete all the files in this folder. You may need to turn on the ability to view hidden files and folders to do this. To do so, double click My Computer, then click Tools and Options. Then click View, and select the option to view all hidden files.
Which version of game do you all have, Retail DVD or STEAM ?
NOW, you must First Manually delete the entire 'Ubisoft Game Launcher' folder, e.g. from C:\Program Files\Ubisoft\Ubisoft Game Launcher. Also remove it from Control Panel----> Add/Remove programs (Programs & Features). Make sure the UbisoftGameLauncher is fully removed from these locations, BEFORE installing it again.
After that again reinstall the Game Launcher from the disk/DVD. Browse the DVD, and go to 'Support-----> Game Launcher', and run the UbisoftGameLauncherInstaller.exe file. Did you download this game from Steam ? STEAM's path should be something similar like this e.g.: C:\Program Files (x86)\Steam\SteamApps\Common\AC2\Redist\GameLaunch er\UbisoftGameLauncherInstaller.exe.
If the above methods still don't work, then you can try deleting the 'Registry' entries of the Launcher, and then do a reinstall of the Game Launcher file. (i.e. remove it from HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Ubisoft\Ub isoft Game Launcher, or HKEY_LOCAL_MACHINE\SOFTWARE\Ubisoft\Ubisoft Game Launcher.).