Windows freezes due to incorrect BIOS date

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Windows freezes due to incorrect BIOS date
Example alt text
Error Details
Operating SystemMicrosoft Windows 10 1909
TypeSystem Freeze
  • Windows freezes while showing the logo (never boots)
  • Extreme and unreasonable CPU usage
  • Missing notifications
  • Messed up icons
  • Non-responsive machine
CauseCMOS clock set to 3001 or greater
Likely Causes
  • Human Input Error
  • Factory irregularities
  • Buggy software in Windows
  • Malware or virus
  • Hardware failure or damage

"... Five hundred dollars in spare parts. Three and a half hours of my time, not including the time spent in emails and phone calls. All because the BIOS date was set wrong."

— Carey Holzman, "Fix Windows 10 Installation Problems", (4 March 2020)

Having an incorrectly set date in the BIOS can cause Windows to function in unpredictable and incorrect ways including crashes, high usage of system resources, missing icons and boot failures. The problem is most common on newly-assembled computers where Windows 10 is being installed for the first time. Under such conditions, the technician or user may be unaware that the date is incorrect. It tends to occur because the time is too far into the future beyond the year 3000. The problem most frequently occurred on Gigabyte motherboards which permitted a date value of 9999 to be entered by a user.[1][2][3][4] Correcting the date/time in the BIOS does not alleviate the issue because Windows presumes the erroneous date to be correct so simply sets the CMOS back to the erroneous date and time.[3]

Windows neither checks nor warns the user of the extreme and irregular date value during installation, so it unlikely that the irregular date would be detected, making it hard to troubleshoot.[2] Similar symptoms, for example, can occur due to power supply issues.[5][2]

Common causes

The only known cause of the bug seems to be having a CMOS date set to the year 3001 or later. Such is a very rare condition so the bug and its implications appear to be largely unknown. Despite this, the affects of having an incorrect clock have been documented, at least, informally on some technical forms.[6] The widespread impact of the bug is unknown, especially considering that commonly reported post-installation freezes are attributed to other causes.[7] Perfectly functioning motherboards may be returned to the point of sale or manufacturer because they are incorrectly diagnosed as having failed.[4]

There are three main ways in which a CMOS clock can be set to an irregular value: (1) accidentally typing in the wrong value (human error); (2) factory irregularities or motherboard faults or (3) buggy software, which incorrectly sets the CMOS clock from Windows itself.

Side affects

A significantly wrong CMOS date and time can cause several problems for the Microsoft Windows family of operating systems including a wide range of network problems. However, beyond the date 18 January 3001, Windows experiences numerous side affects that results in instability, freezes, system crashes and booting problems. Replicating the problem indicated abnormally high CPU usage and failure of critical services within Windows. A perfectly stable Windows system even six months after installation may hang due to this bug. This is because critical services that Windows relies on to start cannot start correctly because the irregular value seems to cause side affects in Windows. The Win32 subsystem, for instance, may not be able to handle the year 3002 AD or later.

CPU usage

When a perfectly running Windows 10 has its time changed through the command line interface on Gigabyte systems to 3001 AD (or later), certain components within Windows seem to stop working. The notification and alerts disappear. Windows Defender reports to be out of date. The fans within the computer may then begin to spin noticeably loud due to the CPU working harder. Even 10 core systems may grind to a halt as resources are pushed to their limits as Windows tries to frantically start many services at once, presumably to update everything. The CPU soon returns to normal operating range once the CMOS year has been reset to a more regular value such as 2020 AD.


The Services Pane. Numbers and letters appended to the Services name. This only occurs when CMOS clock is set to 3001 or later. When resetting the clock back to normal, the services cease to be named in this way.

Multiple services may appear in the list of services with numbers appended to end of the names. The original services without the numbers will not start due to an "unknown error". However, the services with numbers on the end will, indeed be started. When the CMOS clock is reset to a regular value, the services will the numbers at the end will no longer be visible. The normal services will also be started as they should be.


Earlier builds of Windows 10, such as Windows 10 1703 or 180x, seem less affected by this bug. Installing Windows onto Gigabyte systems with an irregular date set does not hang the computer. Windows boots successfully and runs smoothly, despite the irregular date being set. The irregular date also appears in the system tray.

Virtual machines such as VMWare caps the BIOS entry to a limited sub-range between 2018 and 2040. Because of this, setting the CMOS clock to 3001 AD is not possible. Even though, the time/date can be set manually in Windows from the command line, the CMOS does not recognize such value. Instead, the CMOS clock is set to 2018. In Windows, the year 3001 AD appears. Since the CMOS clock is not synced with Windows in the case of VMWare, the system boots. However, immediately, the virtual machine performs very slow. When Task Manager is opened, the CPU usage is maxed out due to extreme CPU usage. The CPU usage gradually normalizes after the date is reset to a regular value.

Ubuntu is not affected by this bug because It sets the year to 2016.


There are two fixes to this problem. The first and least drastic is to simply reset the date/time to their correct values and then delete bootstat.dat to prevent Windows from reapplying the incorrect date at startup. The second is to delete all partitions, reformat the hard disk and then reinstall Windows. The latter is required if the freeze has damaged Windows beyond repair.

Fix 1: Reset time and delete bootstat.dat

1. Reset CMOS Clock

The technician must first reset the clock back to a more regular value.

  • If the BIOS is accessible, then this should be done from the BIOS settings in accordance with the motherboard manual for setting the CMOS clock.
  • If the BIOS is inaccessible, the CMOS clock can be safely changed by booting a Windows installation media. Open a command prompt window by pressing ⇧ Shift+F10 at the same time.
    • Then, in the command window, type date and press ↵ Enter.
    • Type a regular date and accept the new value by pressing ↵ Enter.

2. Delete C:\Windows\bootstat.dat

a) Boot the Windows installer from Windows bootable media

b) Open a command prompt by pressing ⇧ Shift+F10.

c) Find the drive containing a folder called Windows (i.e. C:\Windows) and access the drive by typing C:

d) Change directory by typing cd C:\Windows

e) Delete bootstat.dat file from \Windows folder to stop Windows from updating the CMOS clock by typing del bootstat.dat /a[6]

f) Restart your computer by closing the command prompt program and restarting the computer when asked

Fix 2: Erase Partitions and Reinstall Windows

An optimal solution is to erase all of the partitions of Windows and then install Windows again.[3] This should only be attempted on a new but failing installation of Windows impacted by this bug. Important data should be backed up before erasing any partitions from the drive to prevent data loss.

1. Start Windows installer

Start the Windows installer by booting from the Windows DVD, USB flash drive or from the recovery partition.

2. Backup important data

Backup any important data on the hard disk to prevent data loss. If you do not do this, data loss will result when you delete the partitions.

3. Begin by installing Windows

Follow the setup prompts to install Windows 10/11 onto the computer. When prompted to select a hard disk to install, carefully remove the existing partitions by selecting them one at a time and then pressing the Delete button. Please note that you can only delete one partition at a time.


  1. Holzman, Carey (2020-03-04). LIVE - Windows 10 Y3K Bug EXPOSED!. Event occurs at 11:00. Retrieved 2020-08-13.
  2. 2.0 2.1 2.2 Holzman, Carey (2020-03-04). Fix Windows 10 Installation Problems. Phoenix, Arizona. Event occurs at 15:39. Retrieved 2020-04-18.
  3. 3.0 3.1 3.2 Gatlan, Sergiu (2020-03-02). "Windows 10 Y3K Bug: Won't Install After January 18, 3001". BleepingComputer. Retrieved 2020-08-09.
  4. 4.0 4.1 LIVE - Testing used motherboards purchased at a discount from Amazon Warehouse. Will they work?. Event occurs at 3:58:52. Retrieved 2020-09-22.
  5. Holzman, Carey (Director) (2020-03-04). LIVE - Customer Built a New PC That Won't Work! An eye-opening diagnostic!. Event occurs at 3:45:39. Retrieved 2020-08-13.
  6. 6.0 6.1 B., Mike (2017-03-20). "Windows Keeps Changing The Hardware Clock" (Blog Post). Super User. Retrieved 2020-04-18.
  7. Tim, Fisher (2020-07-20). "Here's What to Do When Your Computer Freezes During Windows Startup". Lifewire. Retrieved 2020-08-09.