Q: What is KB891711.EXE and why is it in my Startup tasklist?
A: KB891711.EXE is an official Microsoft "patch" that only applies to Win98 / Win98SE / WinMe. It is run as a service that protects against an exploit that can place malicious code in cursor and icon files. if you load one of those files, those files can actually execute programs placed on remote computers. This program will cut that off, and should NOT be removed.

For further details, see MS05-002: Microsoft Knowledgebase Article 891711: Vulnerability in cursor and icon format handling could allow remote code execution