I've got this problem that started happening recently.
Overnight, something is happening that makes my taskbar disappear on my laptop. The Start orb is still there, and if I click it, it pops up the start menu, but the whole rest of the taskbar, including the background behind the start orb, is just completely vanished: tray icons, running programs, clock, everything.
I tried killing explorer.exe and restarting it, but it doesn't restart. And after killing it, Task Manager won't let me start ANY programs. It gives no errors, just ... doesn't run them.
Anyone else see this or know what it might be? I'm running Windows 7 RC on an IBM ThinkPad R51 with 2GB RAM.