HP Customer Support - Knowledge Base







HP and Compaq Desktop PCs - The Computer Clock Loses Time (Windows Vista)

This document applies to HP and Compaq desktop computers using Windows Vista.
If the time displayed in Windows does not match the current time, or if the time in Windows has to be reset often, use the steps in this document to troubleshoot these time-related issues.

Step 1: Disabling or enabling Internet time

If Internet time is set and you are connected to the Internet, the computer connects to an Internet time server and synchronizes the time to the time on the server. Internet time can provide an accurate method of keeping time and is normally recommended. However, in some cases, Internet time may actually cause problems. Use the following steps to disable or enable the Internet time setting depending on what is currently selected.
  1. Click Start , click Control Panel, click Clock, click Language, click Region, and then click Date and Time.
  2. Click the Date and Time tab.
  3. Click Change time zone. Make sure the correct time zone is selected. Place a checkmark next to Automatically adjust clock for Daylight Saving Time if it is not already selected, and then click OK.
    Figure : Time Zone Settings
    Time zone setting with Automatically adjust clock for Daylight Savings Time checked
  4. Click the Internet Time tab, and then click Change settings.
    Figure : Internet Time tab with Change settings button
    Internet Time tab with Change settings button highlighted
  5. If it is not already selected, select Synchronize with an Internet time server.
    Make sure the computer is connected to the Internet and click Update Now.
    The computer connects to an Internet server and updates the time on the computer. Click OK and try using the computer for a few days. If time continues to be lost and causes problems, continue using the rest of the steps in this document.
    Figure : Internet time settings window
    Internet Time Settings window with Update now highlighted
    If the computer fails to receive an update from the selected Internet time server, a message opens stating that an error has occurred. Select a different server and try again. If the computer fails to receive an update, Click OK and continue with rest of the steps in this document.

Step 2: Updating the BIOS

If your computer has a BIOS update available, the update may fix time-related problems . To find out if a BIOS update is available for your computer, refer to the HP support document Updating the BIOS.
If the clock continues to lose time and causes problems after updating the BIOS, or you cannot update the BIOS, continue to the next step.

Step 3: Removing and reinstalling Realtime clock

Remove and reinstall Realtime clock by starting the system in Safe mode. Use the following steps to perform this task:
  1. Turn on the computer and immediately begin pressing the F8 key repeatedly until a Windows Start-up Menu appears.
  2. Select Safe Mode and then press the Enter key.
  3. Click Start , and then click Control Panel.
  4. Click System and Maintenance, and click System.
  5. Under Tasks, click Device Manager.
  6. Click the Plus Sign (+) next to System devices.
  7. Right-click System CMOS/real time clock, click Uninstall, and then click OK.
  8. When the System Settings Change window appears, click Yes to restart the computer. The real-time clock reinstalls automatically.

Step 4: Replacing the CMOS battery

Desktop computers contain a battery to keep time in the same manner as a watch keeps time. Like a watch, the battery should be replaced when it runs low on power. Replace the battery using the following steps:
The edges of metal panels can cut skin. Be careful not to slide skin along any interior metal edge of the computer.
This product contains components that can be damaged by electrostatic discharge (ESD). To reduce the chance of ESD damage, work over a noncarpeted floor, use a static dissipative work surface (such as a conductive foam pad), and wear an ESD wrist strap connected to a grounded surface.
The instructions for removing and replacing the CMOS battery, or for clearing the CMOS, vary depending on the model of the computer. For instructions specific to your model, see the Motherboard Specifications document in the Product Information section of this site.
  1. Unplug all cables except for the power cable. Write down each cable location to help you remember.
  2. Unplug the power cable and with the power cable disconnected press the Power button on the front of the computer.
  3. Loosen or remove the screws on the rear of the computer.
  4. Slide the side panel off from the rear of the computer.
  5. Locate the battery. It is a small shiny round metal wafer (like a larger version of a watch battery).
  6. Remember which direction the battery is installed. Usually the engraved side, the positive side, is face up. Remove the battery from the system board.
    Example 1
    Example 2
  7. Call a local computer supply store to see if a replacement battery is available. Use the inscriptions on the battery to describe the battery.
  8. Acquire the battery and replace it in the same socket it was removed from. Make sure the new battery is installed in exactly the same orientation as the previous battery.
  9. Replace the side panel.
    1. Insert the side panel.
    2. Slide it forward.
    3. Fasten the screws to secure the side panel.
  10. Connect all cables and turn on the computer to set the time.






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