This is because the previous step only uninstalls the Acceleration pack or Service Pack.
It is likely you will now see FSX still present in the list.
Fsx acceleration service pack 2 install#
If you have a side-by-side install of both FSX retail and FSX: Steam Edition, make sure you only install the one that you're trying to reinstall! If you have FSX: Steam Edition, you can also uninstall it directly from your games library list within Steam. This may say Acceleration, Service Pack 2, Steam Edition, etc.
You need to do this because many addons (like our own) feature validation protection or registry entries that will get reset when you uninstall, if you leave your addons there, they may fail to reinstall correctly later. Remove any addons you have installed for FSX, including aircraft, scenery, and utilities such as weather addons.