Originally Posted by zebra
Another thing you can check, and I'm assuming you're running a Windows based PC is to make sure that the 'VCS' file extension is being recognized by Windows. Basically, united.com downloads a Vcalendar file (VCS) to your PC, and based on what Windows has set according to the file type, it should run the program that you desire (In this case, make sure Microsoft Outlook is installed).
In order to check this, go to 'My Computer', and click on Tools->Folder Options.
then look for a tab named File Types, and type vcs. It should say 'Opens with:' followed by the program that opens these types of files. In your case, try to select Microsoft Outlook.
Hope this helps.
Zebra - Thanks for your suggestion. I checked the setup as you described and the vcs file confirms "opens with microsoft outlook", so I went back to My Itineraries -> download itin to calendar program -> and a page opens with a list of my on hold itins, and current and past itins. If I select ANY of the current itins, then a page opens the selected itin with an icon to print the E-receipt. No other pop-up appears to move the itin into Outlook. Any other suggestions? Is it worth a call to united.com for technical assistance?