This tip (not mine) works! If you expect to see the CPU graph in your system tray and no longer are seeing it, then try these instructions.
Open the task manager, goto options, UNCHECK 'minimize on use' and 'hide when minimized'.
Close the task manager and reopen it. You should see the cool CPU meter in your
system tray again.
Then reselect 'hide when minimized' so you don't have the taskbar
button when it's minimized.