problem with downloads

Hi,

a frequently asked question I'm sure, but I'm not having any success with downloading new aircraft. i have followed the procedures detailed in some the posts here, but even though I can actually download the aircraft and extract it to the correct folder in FSX , it never appears in the slection panel for aircarft when i re-start the program. I'm using windows vista home premium and winrar to download and manage files.

The aircrfat files seem to be extracting ok and do appear in the SimObjects folder in FSX but they never appear in the aircraft selection panel.

am I missing something here?

many Thanks

roger