This article will be expanded some time in the future.

Occasionally members report that the client continues to run all the time or does not adhere to the preferences selected and saved at the website device profile(s) or local preferences, particularly, not pausing when the computer is being used, speak the mouse or keyboard used. When so:

• Make sure that the option Run based on Preferences has been selected in the BOINC Manager, Advanced View's Activity Menu.
  
  
• For clients above version 5.10.20, verify in the Task or Process Manager that a little program called boinctray.exe is running [applies to Windows Vista and up]. It has nothing to do with the BOINC system tray icon. The helper utility's purpose is to detect mouse and keyboard activity and tell the core client, BOINC.exe about that, so it can act on that, to include adjusting the amount of memory used.
  
  In Windows the quick way to check is to hit the Ctrl-Shift-Esc keys combined to open up the Task Manager and viewing the programs shown under the Processes tab.
  
  If boinctray.exe it is not running, boot the system and restart BOINC for verification. Visit the BOINC program folder if the helper utility exists. BOINC does not warn when not. Report to the BOINC Client Support forum, detailing operating system, client version, e.g. 5.10.45, and how installed, as user, when it is only starting after signing in, or as service aka protected installation.

Also see the FAQ: BOINC ignores "Do work after idle for X minutes" setting .