1a.
If you aren't sure what
you have, or have 2.0b installed already,
download the 2.0a
version super crack.
Open it and extract it to your age of kings main directory. Your will
have to overwrite "empires2.exe" with the 2.0a version of
"empires2.exe". Once you are sure you have 2.0a installed go
to step 1b.
1b.
Once you are
using 2.0a, rename
“empires2.exe” to
“empires2a.exe”, and run “AoKUpdate2.0b.zip”.
After you are done with this step your directory should have
"empires2.exe" and "empires2a.exe" as shown in the picture below.

2.
Go to your AOK directory shown above, and
put both of my batch
files in your directory.
(the files are: “change 2.0a to 2.0b.bat” and
“change 2.0b to 2.0a.bat”) You can see
them in the picture above.
3.
Now just make shortcuts to the
batch files in a convenient spot
like your desktop and you can change back and forth from the 2 versions
easily.
To make shortcuts: One
way to make a shortcut is to select both files, and to hold down ctrl
and shift while dragging them where you want the shortcuts.
Another way is to select both files, and right-click them. A
menu will pop-up and you just select create shortcut. Then
you just drag the shortcuts wherever you want them.