Laptop not keeping time, CMOS battery good

Zoltan Head

Posts: 245   +27
Hi all, a friend has a laptop running XP, the system clock resets everytime it's switched off for more than half an hour or so. I have tried three replacement CMOS batteries (and checked the voltage with a multimeter, 3V or thereabouts), no joy. I have cleaned the battery clip contacts & definitely inserted the batteries right way up, any polite suggestions please?


Posts: 1,808   +250
Have you check the bios to make sure the time is set correctly in the bios? If not windows will not keep the correct time.


Posts: 17,233   +234
The Real Time Clock on the motherboard is probably bad... I imagine that this laptop is rather old now


Posts: 13,141   +6,439
Have you check the bios to make sure the time is set correctly in the bios? If not windows will not keep the correct time.
Windows keeps the correct time by setting the system time (which is also represented by the BIOS). If Windows represents a time you can rest assured, that is the time the system BIOS will represent. Windows does not have an independent time apart from the system time.
  • When Windows loads it will read the time from the system.
  • When you change the time in Windows it will set the system time.
  • This assures the next time Windows loads it will load the correct time.
If the time is not correct then there is a problem with the system time not maintaining the correct time. Whether it be a faulty battery or faulty hardware is the only question. I have had my PC loose system time twice due to system freezing. Time was not lost every time, but that was the cause of my issue which was later found to be incompatible RAM modules. Any system fault that interrupts the system timer will reset the system time. The system faults may not always be evident which would lead to a difficult troubleshooting experience. The most common and easiest solution is a low battery, but that is not always the case. Electrical surges and excessive power ripples in the PSU could also be potential suspects.


Posts: 2,854   +200

Just get the free opensource app called NeTime runs on NetTime is a Simple Network Time Protocol (SNTP) client for Windows 95/98/Me/NT/2000/XP/Vista/7/8 and Server 2003/2008/2012. (32 bit and 64 bit operating systems are both supported) I use this on systems where the system clock time would be off even thought the system battery has been changed. This app
runs as a service and keep the time correct.