Software Update Channels in Internet Explorer 4.01

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Ray Sun
Microsoft Corporation

December 19, 1997

You can use Microsoft® Internet Explorer with Open Software Description (OSD) for two primary purposes:

1. To create software update channels to notify your users about new versions of your software.
2. To describe installation packages to deploy and install files through the Internet.

This article describes the changes introduced in Internet Explorer 4.01 to simplify the creation of software update channels. No changes were made regarding the usage of OSD in Internet installation packages.

In Internet Explorer 4.01, OSD support was improved to make it even easier to advertise new versions of your software to your users. Specifically, you should now be able to deploy a software update channel with few changes (if any) to your existing code. The three main changes are the following:

1. Using OSD-aware shortcuts, users can now be notified of updates to their software program immediately at the execution of the shortcut, which is the best time to remind the user.
2. New versions of ActiveX™ controls can now be installed on the user's machine when the user visits any Web site that uses that control (not just the original page).
3. The Software Distribution Channel API for using OSD has been replaced with the new OSD-aware shortcut technique for software update notification. This means fewer (if any) code changes required to use OSD.

OSD-Aware Shortcuts for Right-on-Time Update Notification

With Microsoft Internet Explorer 4.01, shortcuts have been enhanced (referred to as "blessed" in the Internet Client SDK) to allow software update notification to happen at exactly the right time, when the user is starting your software program. With Microsoft Internet Explorer 4.0, notification had to be done with a call to the API. Now, with version 4.01, Internet Explorer takes care of the work for you. To read about right-on-time update notification in Internet Explorer 4.01, refer to the article, How to Publish Applications to the Internet Using OSD.

ActiveX Control Updates from Any Web Site Using the Control

In Internet Explorer 4.0, if you published a new version of your ActiveX control, the user had to return to your original Web site that hosted the control in order to get it updated. With Microsoft Internet Explorer 4.01, after you advertise the new version, the user will automatically receive the update when he or she visits any Web site hosting your control. To read about control updates in version 4.01, refer to the article, How to Automatically Update an ActiveX Control.

Removal of the API for the Common Usage of OSD

In Internet Explorer 4.0, if you wanted to create software that could check for new versions without launching the browser, you had to call the Software Distribution Channel API, which checked the registry for software update information. With the OSD-aware shortcuts described above, this process is greatly simplified, and the work is done by Microsoft Internet Explorer 4.01 instead.

For more information on these and additional enhancements introduced in Internet Explorer 4.01, see the complete information provided in the MSDN Online Web Workshop.