Problems with A/C add ons

Warning! This flight sim can be addictive.

Panels

FS9.config.

Funny that you should mention FSSound.dll. last night I installed and aircraft that was an exe. and it put an old version of it in my folder. Warning warning... that annoying message.
I went to the main Flight Simulator 9 folder, then to the module folder, removed the FSSound.dll and put it for safe keeping into a separate folder that I had just created for it.
The sim and the sound is fine without it. Try it, if it doesn't work you still have it to put back.

Here is my special ©patented® install procedure, see how it works for you.

You need WinZip to unzip the folders.
You can get the trial one at WinZip it's the best you can use and the trial will last for years.

I think I know what you are asking but I try answering two ways.
One, If you cannot find your downloads to "unzip" them, send them to "My Computer", "My Briefcase" or even to "Desktop".
You can enter them from any of those areas.
I download to a folder that I have in "My Briefcase" it's just handy for me that way.
Installing.
Ok,
I do it a more complicated way, but it works.
Make certain you have a full aircraft not just textures.

Unzip the file and now it's in it's own little window, you work from there. Dump the jpgs.

dblc=double-click

dblc on "My Computer"
dblc on The "C" drive icon.
dblc on "Program files"
dblc on "Microsoft Games".
dblc on "Flight Simulator.

Now you have all the folders laid out in front of you.
Follow the directions in the read-me that came with the aircraft.
Put the gauges in the gauge folder.
Put the effects in the effects folder.
Put the aircraft in the aircraft folder; make certain it has the correct name of the plane.

Now go crash land like I do.