There is also a "clean" way to stop explorer.exe instead of killing it,
goto the "shut down windows" dialog box
press and hold CTRL-SHIFT-ALT then click Cancel on the dialog box,
your taskbar and desktop icons will disappear as explorer exits (start it again as metalj explained)
!! ONLY read further if you KNOW what you're doing !!
FOR Windows NT, 2000, XP, 2003 ...
Explorer.exe is started by userinit, and userinit is started by winlogon upon login of the user.
all of this is configured in the registry under:
HKLM\Software\Microsoft\Windows NT\Currentversion\Winlogon
There is an entry called "Shell" which has explorer.exe in it and an entry "userinit" which has userinit.exe in it.
the program under "userinit" is started once when you log in, and should do its stuff and lastly execute whatever is in "Shell"
the program under "Shell" is then again executed whenever winlogon detects that your explorer has stopped unexpectedly
In other words, if you change for example the "explorer.exe" under "Shell" to "cmd.exe" a command window is started instead of explorer.exe
BEWARE: if some nonexisting program is set in "Shell" you may not be able to login anymore !!!
http://msdn.microsoft.com/en-us/library/aa378750(VS.85).aspx (at the bottom)
