How to uninstall LLVM on Windows

Keep source code and check any compiler paths in build scripts before removing LLVM.

This guide covers LLVM 23.1.3 installed per machine with winget (WiX). The program folder is %ProgramFiles%\LLVM. It has no resident window, and this test found no startup item.

Quit any tool that is still running

Close any open clang, lld or llvm-ml window. This test did not see a resident process.

Remove it with its own uninstaller

A per-machine install needs an administrator to uninstall. Use the product code from this PC's uninstall entry. This test used:

msiexec /x {D42D2D40-9D14-40CA-AA39-61191D9F0543}

You can also uninstall LLVM from Settings, Apps, Installed apps.

Where the data is

After this uninstall the program folder and its usage records were both gone, and the snapshot diff had no rows. No separate user-data folder was written.

Check the result

Get-ItemProperty "HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\{D42D2D40-9D14-40CA-AA39-61191D9F0543}" -ErrorAction SilentlyContinue
Test-Path "$env:ProgramFiles\LLVM"

• No output from that query does not prove the entry is absent when errors are suppressed. Confirm a successful query or an explicit missing-target result; a listed entry means it remains.
• False on the second line means the program folder is gone.

What Mole lists

The selected LLVM program folder was removed and the usage records were already absent. The test recorded no further app-owned residue, but it did not check projects or compiler integrations outside the installation.

These defaults assume Remove data and settings with apps is off. Explicit Select all or Also remove user data can include the listed personal-data rows. Check the selection before confirming. Selected files that Mole removes go to the Recycle Bin; selected registry entries are backed up before removal. The vendor uninstaller has its own deletion behavior.

What this test covered

Recorded on 2026-10-19: LLVM, version 23.1.3, machine-wide, MSI, winget package LLVM.LLVM. The evidence comes from an ARM64 Windows test environment and a development build of Mole. It does not certify the current downloadable package or removal of real signed-in accounts, synchronized data or production projects.

Vendor documentation. The paths and removal results above are observations from the Windows test unless explicitly attributed to the vendor.