ID: Q172080
The information in this article applies to:
After you uninstall Task Scheduler, the System Agent icon does not appear on the taskbar. If you attempt to start System Agent by using the Start menu, you may receive the following error message:
   Cannot restart System Agent, reinstall MS Plus
   Essential file is missing on bootup
   Sage.vxd
This behavior can occur if you uninstall Task Scheduler. Task Scheduler replaces System Agent, but System Agent is not restored when you uninstall Task Scheduler.
To resolve this issue, reinstall System Agent. For information about reinstalling System Agent, please see the following article in the Microsoft Knowledge Base:
   ARTICLE-ID: Q133191
   TITLE     : Reinstalling System Agent Without Losing Scheduled Tasks
Task Scheduler is an Internet Explorer component that you can install using the Add/Remove Programs tool in Control Panel after Internet Explorer is installed.
For information about how to add or remove Internet Explorer components, see the following article in the Microsoft Knowledge Base:
   ARTICLE-ID: Q171229
   TITLE     : How to Add and Remove Internet Explorer Components
Keywords          : kberrmsg kbtool msiew95
Version           : WINDOWS:4.0
Platform          : WINDOWSLast Reviewed: March 17, 1999