An awesome an idea called rebooting your day, from a list of programmer productivity tips.:
As a last resort, reboot your day. This is something I do not just with work, but any time a day is going so incredibly badly it just can’t be saved. Turn off the lights and take a quick nap. 20 minutes is best. When you get up, take a shower, make a small breakfast, and just go through your morning routine as if it were the first time. Try to forget anything prior even happened.
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(*) Rebooting, the act of re-starting a computer system.
  • A Hard reboot requires powering the system off, and then on again to restart it
  • A Soft reboot re-starts the system without powering off

(**) Ctrl+Alt+Dell
"I may have invented Ctrl-Alt-Del, but Bill [Gates] made it famous"
by David Bradley, a designer of the original IBM PC, alluding to the three keystrokes required to logon to a Windows operating system; the jab has often been mispercieved as a jab at the supposed instability of Windows as Control-Alt-Delete also reboots the operating system (Windows ME or older) or opens a task manager to kill crashed programs (Windows 2000 or newer)... [wiki]