A constantly running Windows fan typically results from software or hardware issues triggered by system updates, driver conflicts, or thermal management problems. The most common causes include Windows 11 updates installing generic drivers that misregulate thermal performance, background processes consuming excessive CPU resources, or outdated BIOS/firmware failing to optimize fan control. Users frequently report this issue after major Windows updates (like version 24H2) or clean OS installations, where the fan remains active despite low CPU usage readings in Task Manager.

Key findings from the sources:

• Driver conflicts are the primary culprit, with Windows 11 often defaulting to non-optimized generic drivers for specific hardware ^[1][7]
• Background processes like "System Interrupts" or the Windows 11 Widgets feature can spike CPU usage without visible tasks ^[3][5]
• Power settings default to performance mode in Windows 11, increasing thermal output ^[7][8]
• Hardware factors like dust accumulation or degraded thermal paste can exacerbate software-related fan issues ^[3][10]

Root Causes and Solutions for Constant Windows Fan Operation

Software-Related Triggers and Fixes

Windows 11 updates frequently introduce fan control issues through driver incompatibilities or new background services. The version 24H2 update, for instance, caused persistent fan activity on devices like the Surface Laptop 4 even when CPU usage appeared normal in Task Manager ^[1]. This discrepancy occurs because Task Manager may not reflect all system-level processes consuming resources. The Windows 11 Widgets feature, enabled by default, has been specifically identified as a CPU-intensive process that triggers constant fan operation on Lenovo Ideapad models ^[5].

To address software-related causes:

• Update or roll back drivers: Manufacturer-specific drivers often resolve generic driver issues. Lenovo users reported success after installing drivers directly from Lenovo's support site rather than relying on Windows Update ^[5]. For persistent issues after updates, rolling back to a previous Windows version (via Settings > Recovery) has proven effective ^[1]
• Disable resource-heavy features: The Windows 11 Widgets dashboard consumes significant CPU resources. Disabling it via Settings > Personalization > Taskbar > Widgets reduced fan activity for multiple users ^[5]
• Adjust power plans: Windows 11 defaults to "Balanced" or "Best Performance" plans that maximize CPU potential. Switching to "Power Saver" mode (Control Panel > Power Options) consistently lowered fan speeds in reported cases ^[7][8]
• Monitor background processes: "System Interrupts" appearing in Task Manager often indicate driver conflicts. Users should check Device Manager for devices with warning symbols and update those drivers specifically ^[3]

The YouTube guide emphasizes managing background processes through Task Manager (Ctrl+Shift+Esc) to identify and end unnecessary applications, particularly those running at startup that may not be visible in normal operation ^[6].

Hardware and Thermal Management Factors

While software issues predominate, hardware conditions significantly contribute to constant fan operation. Dust accumulation in fans and heat sinks creates insulation that prevents proper heat dissipation, forcing fans to run continuously ^[3][10]. A Lenovo community discussion specifically notes that fans filled with dust must spin faster to achieve the same cooling effect, often becoming noisy in the process ^[9]. Thermal paste degradation between the CPU and heat sink similarly reduces heat transfer efficiency, particularly in older laptops.

Hardware-related solutions include:

• Physical cleaning: Using compressed air to remove dust from vents and fans every 3-6 months. Dell's troubleshooting guide provides specific instructions for safely cleaning air vents without damaging components ^[10]
• Thermal paste replacement: For laptops over 2-3 years old, replacing dried thermal paste can restore proper heat transfer. This requires technical expertise as it involves disassembling the device ^[3]
• Ventilation checks: Ensuring laptops aren't used on soft surfaces that block airflow. HP recommends maintaining at least 2 inches of clearance around ventilation areas ^[8]
• BIOS updates: Manufacturer BIOS updates often include improved thermal management algorithms. ASUS specifically advises updating BIOS as a primary troubleshooting step for fan issues ^[4]

The ASUS support document highlights that fan speed should correlate with CPU/GPU temperature readings. Users can verify this relationship using hardware monitoring tools like MyASUS or HWMonitor. If fans run at maximum speed even when temperatures are normal (below 60°C for most CPUs), this indicates a sensor or control system failure requiring professional service ^[4].