Task Manager displays CPU uptime in the format of days, hours, minutes, and seconds to show how long your computer has been running since the last full restart. When you see uptime like 1:01:07:05, it means your system has been active for 1 day, 1 hour, 7 minutes, and 5 seconds continuously. However, many users notice their cpu uptime not resetting after restart even when they shut down or restart multiple times throughout the day. This confusing behavior occurs because Windows uses a feature called Fast Startup that performs a hybrid shutdown instead of a complete system restart.
Windows Fast Startup Hybrid Boot System
Fast Startup, also known as Hybrid Boot, was introduced in Windows 8 and continues through Windows 10 and Windows 11 as a default enabled feature. This power management technology saves the Windows kernel and loaded drivers to a hibernation file called hiberfil.sys when you shut down your computer. Instead of performing a complete shutdown that terminates all processes, Fast Startup logs off the current user and puts the kernel into hibernation mode. When you power on your computer again, Windows restores the saved kernel state from the hibernation file rather than initializing everything from scratch. This process significantly reduces boot times but creates the side effect of maintaining the uptime counter across shutdown cycles.
Why Task Manager Uptime Counter Keeps Running
The task manager uptime counter windows continues counting because the kernel session never fully terminates when Fast Startup remains enabled. During a traditional full shutdown, Windows closes all processes, unloads drivers, and completely powers down the system before clearing all memory. With Fast Startup active, the shutdown process only affects user sessions while preserving low level operating system components in the hibernation file. This preservation means the kernel technically never stops running between shutdown and startup, so the uptime counter treats it as continuous operation. The restart option, however, always performs a full reboot regardless of Fast Startup settings, which is why restart typically resets the uptime while shutdown does not.
| Shutdown Method | Resets Uptime | Speed | Full Kernel Restart |
|---|---|---|---|
| Shutdown with Fast Startup | No | Fast | No |
| Shutdown without Fast Startup | Yes | Slower | Yes |
| Restart Option | Yes | Medium | Yes |
| Shift + Shutdown | Yes | Slower | Yes |
Disable Fast Startup Windows 11 and 10
To permanently fix the uptime reset issue, you need to disable fast startup windows 11 through the Control Panel power settings. Open the Start menu and search for Control Panel, then navigate to Power Options. Click on "Choose what the power buttons do" on the left sidebar, then select "Change settings that are currently unavailable" at the top of the window to unlock the shutdown settings. Scroll down to find the checkbox labeled "Turn on fast startup (recommended)" and uncheck it. Click Save changes to apply the new configuration. After completing these actions, perform a full shutdown by clicking Shut down from the Start menu, wait 10 seconds, and power on your computer again. Check Task Manager by pressing Win + X and selecting Task Manager, then navigate to the Performance tab and click CPU to verify that uptime now shows only a few minutes.
Shutdown Command Full Restart Windows Alternative
If you want to keep Fast Startup enabled for faster boot times but occasionally need a complete restart, you can use the shutdown command full restart windows method through Command Prompt. Press Win + R to open the Run dialog, type cmd, and press Ctrl + Shift + Enter to launch Command Prompt with administrator privileges. Execute the command shutdown /r /f /t 0 to force an immediate full restart that bypasses Fast Startup. The /r parameter specifies restart, /f forces running applications to close, and /t 0 sets the timer to zero seconds for immediate execution. For a complete shutdown instead of restart, use shutdown /s /f /t 0 which performs a full power down. You can create a desktop shortcut for this command by right clicking the desktop, selecting New, then Shortcut, and pasting the shutdown command as the location.
Systeminfo Check Boot Time Verification
To verify your actual system boot time and confirm whether uptime resets properly, use the systeminfo check boot time command through Command Prompt or PowerShell. Open Command Prompt by pressing Win + R, typing cmd, and hitting Enter. Type systeminfo | find "System Boot Time" and press Enter to display the exact date and time when your system last booted. This information shows the true boot time regardless of what Task Manager displays, helping you identify whether Fast Startup is interfering with normal shutdown operations. The command provides accurate boot time data even when the uptime counter shows incorrect values.
Quick Full Shutdown Using Shift Key
Windows provides a convenient shortcut to perform a full shutdown without permanently disabling Fast Startup. Hold down the Shift key on your keyboard before clicking the Shutdown option in the Start menu, and continue holding Shift until the computer begins powering down. This keyboard combination forces Windows to bypass Fast Startup for that single shutdown session, ensuring a complete kernel termination and memory clearance. The next time you power on your computer, the uptime counter will start from zero. This method works from the Start menu, the login screen, or the screen that appears after pressing Ctrl + Alt + Delete.
Summary
CPU uptime not resetting after restart occurs because Windows Fast Startup hibernates the kernel instead of performing a complete shutdown. You can fix this by disabling Fast Startup in Control Panel power settings, using the shutdown /r /f /t 0 command for full restarts, or holding Shift while clicking Shutdown for one time full shutdowns. Verify actual boot times using the systeminfo command to confirm your system restarts properly.
Frequently Asked Questions
Why does restart reset uptime but shutdown does not?
The restart option always performs a full kernel reload regardless of Fast Startup settings, while shutdown with Fast Startup enabled hibernates the kernel session instead of terminating it completely.
Will disabling Fast Startup slow down my computer significantly?
Disabling Fast Startup adds several seconds to boot time depending on your hardware, but the difference is typically minimal on modern computers with solid state drives.
Can I check uptime history for previous days?
Yes, you can view boot and shutdown events in Windows Event Viewer under Windows Logs, System, filtering for Event IDs 6005 for boot and 6006 for shutdown.
Does Fast Startup affect Windows updates?
Fast Startup can interfere with update installation because updates often require complete system restarts, which is why Windows automatically performs full shutdowns when installing updates.
What happens if I force shutdown by holding the power button?
Forcing shutdown by holding the power button performs a hard shutdown that resets uptime but can cause data corruption or file damage because applications cannot save properly.