bmupdate.exe definition:

bmupdate.exe is a spyware-related executable file, and is installed and used by adware BookmarkExpress. It is a dangerous process and may be harmful to your system and your privacy if left unremoved.

If you happen to detect bmupdate.exe in your process library (aka the Task Manager), be sure to remove it or use an automated anti-spyware tool for its removal (recommended), as the presence of bmupdate.exe in your task manager may indicate that your system is infected by multiple spyware or adware parasites.