I was able to restore battery meter icon on Acer aspire runningXP SP3 by doing the following:
Ctrl-Alt-del all at the same time
Click "processes" tab
scroll to and highlight "explorer exe"
Click end process
Click "File" "New Task"
cut and paste, or type: explorer.exe
Click "OK"
Ctrl-Alt-del all at the same time
Click "File" "New Task"
cut and paste, or type: systray.exe
Click "OK"
Source: Bruce
http://en.kioskea.net/forum/affich-53991-icon-bar-has-disappeared#
Hope this helps, Gerry Cornell