My laptop clock keeps dropping back an hour

Hello Joanne,

Thank you for posting your query on Microsoft Community.

There are three main reasons as to why your computer Clock loses its time.

1. CMOS Battery

This is the most likely scenario, especially if your computer is not brand new.

The CMOS battery sits on your computer’s motherboard and provides power to the CMOS chip. The CMOS chip stores information about the system configuration, including the date and time. If the battery goes bad, the chip starts losing information and one of the symptoms is that your computer no longer maintains its time and date.

2. Time Zone

This is an easy to fix cause for when your computer clock loses time.

Your computer may simply be set to the wrong time zone and every time you fix the time, it resets itself to that time zone when you reboot. If the minutes are correct and only the hour is bad, that’s probably the issue you’re dealing with.

In Windows you can easily fix the time zone. Right-click the system clock in your taskbar and select > Adjust date/time. Under the headline > Time Zone check whether the information is correct. If not, click the > Change time zone button and set your time zone. Don’t forget to confirm your changes.

3. Malware

This is the least pleasant and most difficult to manage scenario.

Your computer may have been hijacked by a virus that messes with your computer time

I would suggest you to follow the methods given below and check.

Method 1.

Step 1. Try to go into safe mode and check.

Boot the computer in Safe mode and check if the issue persists. Safe mode is a diagnostic mode in which you are logged in with only necessary minimal services and drivers enabled. Check if the issue is reproduced.

To go into safe mode refer the link given below

Try to go into safe mode with networking and check.

http://windows.microsoft.com/en-us/windows-8/windows-startup-settings-safe-mode

If the problem does not exist in safe mode, try to perform a clean boot and check.

Step 2: Perform Clean Boot.

Placing your system in Clean Boot state helps in identifying if any third party applications or startup items are causing the issue. Check this issue in clean boot state.

Refer: How to perform a clean boot in Windows

http://support.microsoft.com/kb/929135

Note: After clean boot troubleshooting step, follow the section "How to reset the computer to start as usual after troubleshooting with clean boot" in the provided link to return your computer to Normal startup mode.

If issue still persists try method 2.

Method 2. Microsoft Safety Scanner. I would suggest you to perform a full system scan using the Microsoft Safety Scanner to eliminate any issues related to virus/malware.

Microsoft Safety Scanner http://www.microsoft.com/security/scanner/en-us/default.aspx

Note: Any data files that are infected may only be cleaned by deleting the file entirely, which means there is a potential for data loss.

The Microsoft Safety Scanner expires 10 days after being downloaded. To rerun a scan with the latest anti-malware definitions, download and run the Microsoft Safety Scanner again. 

Hope this information is helpful. Please do let us know if you need further assistance with Windows.