Update tab is required to set and get the schedule and to do the Manual update.

The same issue is reproducible on all the window's OS (XP, vista etc.)
How to reproduce

1.) Install 6u18 b04 pit build form this location
http://j2se.east/arc/1.6.0_18/nightly/2009-10-19

2.) Uninstall JRE

3.) Install JRE again.

4.) After JRE is installed open Java Control Panel (JCP).

Expected Behavior
JCP should have update tab

Actual Behavior:
Update tab is not showing up in JCP