It sounds like you have installed an application that uses Adobe AIR and that application has set itself to launch when you login to your computer. Somehow that application has stopped working, so when the AIR runtime tries to start it, the process fails and AIR puts up the error pop-up.
To fix this, you will have to determine what application is failing and remove or reinstall that. Adobe AIR is just the messeneger here, removing or reinstalling AIR won't help.
If you go to the Control Panel > ADD and Remove Programs (I'm presuming that you are using Windows since you didn't say), and tell it to remove Adobe AIR, the uninstall dialog for AIR should give you a list of the the currently installed applications that use AIR. Most likely, the culprit is one of those.
Sorry for bringing up an old thread and the late reply.
Adobe air gets installed by default with Adobe Reader im pretty sure.
Try uninstalling Adobe Reader and reinstalling, hopefully it fixes the problem.
If you don't have this problem hopefully it helps someone else.
Have a good one!
Download a program that cleans your computer like Ccleaner it might also help this problem or other problems you dont know about.