How to uninstall Fiddler Classic on Windows

Save captured sessions, turn off Fiddler capture and confirm normal browsing works before closing Fiddler Classic.

This guide covers Progress Telerik Fiddler Classic 6.0.20262.10021 installed for the current user with winget (NSIS). The program folder is %LOCALAPPDATA%\Programs\Fiddler. The main window was usable without signing in.

Quit Fiddler first

Stop capturing in Fiddler, then quit. This launch started capturing immediately and set the current user's WinINET proxy to 127.0.0.1:8888. After quit that proxy was still on, and this test turned it off afterwards. If pages fail to load after you quit, check Settings, Network and internet, Proxy, in case it still points at 8888.

The first run shows AppContainer Configuration. The default button is No. This test did not click Yes or Cancel.

Remove it with its own uninstaller

A per-user NSIS uninstall does not need an administrator. This test used:

& "$env:LOCALAPPDATA\Programs\Fiddler\uninst.exe" /S

You can also uninstall Progress Telerik Fiddler Classic from Settings, Apps, Installed apps.

Where the data is

After this uninstall the program folder was gone. The two Start menu shortcuts and the Fiddler.ArchiveZip protocol were listed and were already gone.

HKCU\Software\Microsoft\Fiddler2 was still there, with ImagesMenuExt, MenuExt, Orchestra and UI under it. Orchestra holds DPAPI values for this PC. The uninstall did not delete these keys.

Check the result

Get-ItemProperty "HKCU:\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\Fiddler2" -ErrorAction SilentlyContinue
Test-Path "$env:LOCALAPPDATA\Programs\Fiddler"
Test-Path "HKCU:\Software\Microsoft\Fiddler2"
Get-ItemProperty "HKCU:\Software\Microsoft\Windows\CurrentVersion\Internet Settings" | Select-Object ProxyEnable, ProxyServer

• 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 from the second means the program folder is gone.
• True from the third means those registry keys are still there.
• ProxyEnable 0 on the last command means the proxy is off.

What Mole lists

Program files, protocol and usage records were removed; shortcuts were already absent. ImagesMenuExt, MenuExt, Orchestra and UI under HKCU\Software\Microsoft\Fiddler2 were not listed. The test also found that the Windows user proxy could remain enabled after Fiddler exited, so check it separately rather than assuming uninstall resets it.

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: Fiddler Classic, version 6.0.20262.10021, per-user, NSIS, winget package Telerik.Fiddler.Classic. 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.