The following Windows Shortcut Key combinations are particularly useful for continuing to use a system that has begun to crash, or has had certain functions disabled by a virus, or just doesn't have the taskbar set up nicely:
Windows-D: Iconify all windows Pretty Darn Quick, in other words get the desktop
Alt-Tab: Shift between running (or dying) applications
Ctrl-Esc: Gets the start menu. For instance if the mouse is dead, you can get this and navigate using the keyboard and arrow keys.
Ctrl-Shift-Esc: Gets the task monitor even if it's not possible to get it by other means
