Windivert Driver Cannot Be Installed You Must Restart Your Computer -

WinDivert operates by installing a kernel-mode filter driver (typically windivert64.sys on x64 systems) that hooks into the Windows networking stack. Unlike user-mode libraries, kernel drivers require strict adherence to Windows Driver Signing, proper service control management, and conflict-free resource allocation.

The error message appears under several scenarios:

Crucially, the prompt to restart is not merely a suggestion but an indication that Windows has marked the driver for pending deletion or update, requiring a reboot to finalize file operations.

WinDivert is normally signed, but if you have a very old or modified version, you may need to allow unsigned drivers.
Temporary only – restart with advanced boot: WinDivert operates by installing a kernel-mode filter driver

Only do this if the problem persists and you trust the source of WinDivert.

To verify that system files are not corrupted, perform the following:

Since Windows 10 (1607), 64-bit versions require kernel drivers to be signed by Microsoft’s Hardware Dev Center. While WinDivert uses a legitimate test certificate, some enterprise systems enforce strict attestation. If signature validation fails, Windows disables driver load without a reboot, but the installer message may incorrectly genericize the failure as a "cannot install – restart required." Crucially, the prompt to restart is not merely

When Windows updates a driver, it often marks the old driver file for deletion upon the next reboot. If you try to install a new version of WinDivert before rebooting, the installer detects that the old driver is still "pending deletion" (locked). The installer cannot overwrite a file that is scheduled to be removed, so it aborts with this error.

Windows maintains a PendingFileRenameOperations registry key (under HKLM\SYSTEM\CurrentControlSet\Control\Session Manager). If a previous installation attempted to overwrite windivert64.sys but the file was in use, Windows schedules a replacement on next reboot. Subsequent installers detect this pending operation and demand a reboot before proceeding.

This is the most common reason the error persists. By default, Windows 10 and 11 use a feature called Fast Startup. When you click "Shut Down," Windows doesn't actually perform a full cold boot; it saves the system state to a file to load faster next time. Only do this if the problem persists and

If the driver installation is stuck in a "pending" state, a standard shutdown won't clear it.

How to do a "Hard" Restart:

Alternatively, open Command Prompt as Administrator and type: shutdown /s /f /t 0 to force a complete shutdown.