You might be asking what does “Please install Warcraft III before installing The Frozen Throne.” means and why am I posting it? Oh well you probably encountered the error message above if you try to install the frozen throne expansion to Warcraft III in Vista.
I got the same error when I try to install the TFT expansion after Reign of Chaos. But I fixed it with a help from nalle from gamerzplanet.net.

Here’s the solution to this problem and modified a little, thanks to nalle.

  1. First make a register keys.
    To do this you need to create a .key file, open notepad then copy and paste the following:

    Windows Registry Editor Version 5.00

    [HKEY_LOCAL_MACHINE\SOFTWARE\Blizzard Entertainment]
    [HKEY_LOCAL_MACHINE\SOFTWARE\Blizzard Entertainment\Warcraft III]
    “InstallPath”=”F:\\Warcraft III”
    “Program”=”C:\\Warcraft III\\Warcraft III.exe”

    Then save as .key, e.g. TFTFix.key

  2. Double click TFFTix.key to merge, or right click then merge. Note: Please be careful with this, if you are unsure what you are doing just add the registry keys to registry editor, this might be safer for you.
  3. Create 2 files in your windows directory:

-War3Unin.exe
-War3Unin.dat
Those files are allowed to be empty but are REQUIRED!!!

Now try to install Frozen Throne again, the message you should get now is “Install Frozen Throne” or something like that.

This guide involves updating your registry, do at your own risk.