run or dont run option while picking some planes

Have you ever had this? Well sometimes if you have downloaded a plane there will be a dont run and run sometimes both will work and sometimes only one. In this case the dont run for me worked but I hit always run wilco products and was wondering is there anyway I can change that because I dont see that anymore when I choose the plane.

Is this :: http://flyawaysimulation.com/postt27666.html ...the same issue we're dealing with?

Almost, this one also happens to me but isnt just about the wilco airbus problem. I get it sometimes when I download freeware aircraft and then I remove them because they dont work or I dont like em.

Ok then let's look just at the freeware a/c that don't work.
Keep in mind though that in this instance I'm thinking in terms of fs9 as I haven't experienced the same situation in fsx yet.

In fs9, freeware a/c often require modules such as FSSound.dll. In most cases the uploader will include that .dll in the .zip file, but not always. This means that if you install several a/c with the FSSound.dll, you'll be prompted whether you want to overwrite or not: BECAUSE you need only one of them in your Modules folder.

Ok, back to the beginning... let's say this is the first time you install an a/c with the FSSound.dll. Now you load FS, you select your new a/c and the next thing you see is the Error Message asking you whether you want to load that "foreign - alien - scary" object (Module). I think you get a warning at the same time regarding compatibility bla, bla... : Ignore the warning and load, because if you click NO, the a/c won't work. Simple.
You will get the prompt (Warning Message) each time you load the a/c unless you add an entry into the fs9.cfg file. This entry in the fs9.cfg will cause fs9 to recognize the Module and therefore not prompt you any longer. The point to remember is that you must load for the a/c to work.

Now why would fs9 do such a stupid thing... Warning you of incompatibility issues but when you give in to the Warning the a/c won't work; yet if you go against the Warning, everything is working just fine???

The FSSound.dll (and a few others) date back to pre-FS9 times and FS9 won't recognize them. That's all there is to it.

Now remember, everything I've outlined pertains to fs9. How those Modules affect FSX or whether they need to be updated I don't know.

If I encountered the situation with freeware and FSX, I'd experiment but ONLY by ways of manual installation.
Most payware add-ons are in a different league, the installers overwrite new files with old ones at times and then you're in real trouble because you didn't backup the original ones. Nobody can blame you either, because by just looking at the installer you have no way of knowing what kind of files are going to be installed and/or used and overwritten.