After downloading and running AdobeAirInstaller.exe I was suprised, and eventually incredibly frustrated, to finds that the file type .air was not being associated with the AIR program (on Windows Vista)
It didnt help that Adobe themselves dont seem to be trying too hard to fix the problem:
The .air file extension does not register on Windows Vista (Adobe AIR)
"This is a known issue on Windows Vista and there is currently no solution."
But happily a solution is a hand:
Install Adobe AIR.
Right-click on your .air file and selected: 'Open with' > 'choose default program'
Browse to: Program Files\Common Files\Adobe AIR\Versions\1.0\Adobe AIR Application Installer.
Click 'open' & then 'ok'.
You .air extenstion should now be associated with the AIR program.
NOTE: Strangely, a search for 'air' within my Windows Vista will not return a result for the file named 'Adobe AIR Application Installer'. Making it very hard to find the AIR executable!