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.

If the error persists, the most effective fix is often to disable Memory Integrity, a core security feature in Windows.

Go to > Advanced options > Startup Settings > Restart .

The WinDivert driver may already be running because another application (for example, a VPN client running in your system tray) is using it. You cannot install a new driver over an active one. The installer detects the driver is already loaded and refuses to proceed.

Ensure WinDivert.dll , WinDivert.sys , and WinDivert.inf are all in the same folder as your application. On 64-bit systems, you often need both WinDivert32.sys and WinDivert64.sys available.

Alternatively, you can update the driver manually. Go to the official WinDivert GitHub releases page. Download the latest binary package (usually a .zip file).

If you are using a niche, customized, or older version of WinDivert that lacks an official digital signature, Windows will block it at the kernel level. You can temporarily disable this enforcement to test if it solves the issue.

With the exact error code and message in hand, you can perform a more targeted web search for a solution or return to the appropriate solution in this guide.

Scroll down to and click Add or remove exclusions .

The error "WinDivert driver cannot be installed, you must restart your computer"