I remember my younger brother thinking he was all smart by putting a BIOS password on my PC just to make me mad. This was due to my parents having me put one on their computer to keep him off .. since his grades were bad.
Lovely family love eh? hehe..
I guess he didnt figure out how to reset it.. because the BIOS password stayed on their PC.. but I did pop my CMOS battery and worked like a beauty. Nothing wrong with doing that.
Keep in mind that occasionaly you actually have to replace that battery at one point if you use a motherboard for years. And if your clock keeps resetting every time you start your PC thats a good sign