System not starting

If there is a wrong configuration in your cmos setup, it may ask you to enter in to rectify the problem. If you have a low cmos battery this will result in the same effect, but normally it will tell you during the POST if the battery is low.

You have not given much other info to work with ie the age of the machine or the motherboard manufacturer.

I suggest that if you are a experienced computer user, check your cmos settings anf if all fails load the factory defaults. Your motherboard handbook should have a beep error code list

hope this helps

The root cause of this error is usually failure of the CMOS memory backup battery.

Clean the contacts, and install a new battery.

Then, go into BIOS setup, and set the parameters for your system.

The reason it stops, is that the computer nolonger knows what hardware is installed.

There are a couple of TechRepublic articles on adjusting BIOS settings. If you are not familier with the BIOS setings, I suggest that you read them first.
The manual for your PC / motherboard should alsogive you some ideas for how to set options in the BIOS settings.
There are also guides that can be downloaded from the Award, AMI, and Phoenix web sites.

The TR articles are;
learn the basics of bios settings
speed boot time by tweaking the bios

I have found that you need to use all lower case letters to search the TR article archives.

If the CMOS has been changed or needs to be set up, do not do a resume. Usually, you can do a F2 to enter set up and make the necessary changes. Refer to your motherboards user manual for specific settings. Usually, the number one issue is to detector identify your hard drives. Otherwise your system will not operate because it will not be able to find the MBR and the system files necessary to operate.

As far as why you are getting this error? How old is your motherboard? If greater than 3 years you may have to have the back up batter replaced. This could be as simple as having to pop the battery out and put in a new one to having to desolder the old one and resolder a new one. If your environment is really dry and you have carpeted floors, a small static charge could have scrambled the CMOS settings. If it is a constant problem, keep a humidifier in the room and keep the humidity in the 45-55% range.