If you're computer has issues booting or doesn't keep time, a secret battery may be to blame. Learn all about CMOS.
CMOS Battery Can Cause Lots of Problems
My Wii Runs On A Battery?
If your Wii dies, and it hasn't been mistreated, odds are that it's your CMOS battery. Here are some simple instructions for finding and replacing your Wii's CMOS battery.