It is an add-on installer for people who have downloaded Modred's Aces over Europe. The B24 single skin is now upgraded to a multi-skin.
For many years we have advised people against installing EAW as a program because of issues with Windows and "ini" files.
The trick is to copy the installed EAW folder and upgrade the copy. Then the installed EAW can be un-installed.
I have un-installed AoE, but I have a my "dir.set" version of AoE in my 1.28c folders
Edit:
Moggy: there is a "B24MS.zip" file in your folder at the Gen