I am having an issue with a computer I have been using without any problems. I had it unplugged for a few months and went to boot it up. Now it will only boot up or turn on (fans spinning, hard drive boots up) if I remove the CMOS BATTERY and put it back in. I can do a system restart from there and it will restart with no problem. But if I do a shutdown of "turn off" as windows calls it the system will not start up unless I pull the CMOS battery out again and replace it, then it boots up fine, with a message that the CMOS battery has been removed of course.

Anyone have any ideas?

Thanks for your help in advance.Did you check or replace the battery?i have not done either how would you check that battery?  This is the original battery.If you have a voltmeter, a good battery will measure 3.0VDC.  If not, get a new battery, most likely a CR-2032 available in any drug store.I checked with a meter and it was hovering right around 3 Volts.Post your hardware specs...  List ALL devices installed on your computer..

I'm THINKING that when your computer is boots up (with a CLEAN slate in CMOS RAM) it updates the hardware in the cmos inventory with the current hardware on your system, but one of those hardware components may be faulty so it interferes with the boot process.  Therefore when you clear cmos, that faulty hardware is not interfering and lets you boot..  1 Dvd-Rw
1 80 gig hard drive - Has Windows XP on it
2 200GB drives running raid

I know the hard drives are working fine because I am able to access them all.  The DVD-RW also shows up in the filesystem through windows explorer (start -> explore)

Let me know if you need any additional information.Just for clarification...   when you do not remove the CMOS battery, how far does it get into the boot process?  Is there any indication of power?I think he said it won't turn on at all, but let's hear it from him.  Please also supply make and model number of this computer.

Edit:
Are you doing a Shutdown or Standby?
Try a Full Reset:  http://www.dewassoc.com/support/bios/bios_password.htmyes            we need more INPUT  Thanks everyone for the input.  The make is a custom build but the specs are intel D945GNT Motherboard , pentium 4 processor, 1GB crucial memory.  Let me know if you need me to be more specific than that.  Again this machine ran for a year or 2 fine, and then I had it unplugged for about a year or so.  I would boot it up every few months or so to do some things on it but this problem just recently started when I tried to boot it up yesterday.

For the other questions If I DO NOT remove the cmos battery it does not even boot up, turn on, ect.  The fans do not spin hard drives don't boot ect. 

Once I do boot up after removing the cmos battery everything runs normally until I do a system shutdown.  Then I have to remove the cmos battery again and then I can get it to boot back up.  If I only do a system restart it will restart as normally and restart and REBOOT normally.I'm missing something:

1.  Remove battery to start up.
2.  Perform shutdown.
3.  Remove battery again to start up.

At what point is the battery installed?I think he means that he puts the cmos battery back in, immediately after he removes it...  otherwise there would be no CMOS battery to take out next time he tried to power on the computer 


After reading you post there is still something not clear.
Do you mean:
A. You remove the battery, put it back and it boots fine first time. After power off and power on it does not boot up next time. You have tried this several times. Like ten times. Every time it will boot right only the first time after you reset the CMOS  the normal way.
- OR -
B. You remove battery, leave it out, it boot s up. You power off, battery still out. you power on again and it boots up. You can boot again and again whale the battery is out and it always works. You tried this several times. Like t en times.


Yes, ten times. unless you have perfect  concentration, no distractions and a photographic memory, two or three times is not enough when doing tough nut diagnostics. Do you make lab notes? Please don't take offense, just asking.

If you can answer this,  someone here will know what is going on.
So he's putting the battery back in while the computer is ON?
He says the battery reads 3V, but given the load shown below, I'll bet it drops below 3.0 when installed.  For $3-4, try a new battery.

Intel® Desktop Board, D945GNT, Technical Product Specification
1.5.4 Real-Time Clock, CMOS SRAM, and Battery
A coin-cell battery (CR2032) powers the real-time clock and CMOS memory. When the computer
is not plugged into a wall socket, the battery has an estimated life of three years. When the
computer is plugged in, the standby current from the power supply extends the life of the battery.
The clock is accurate to ± 13 minutes/year at 25 ºC with 3.3 VSB applied.
NOTE
If the battery and AC power fail, custom defaults, if previously saved, will be loaded into CMOS
RAM at power-on.