Fiddler won't start saying there's a machine-wide installation

[Sameera]

I've been using Fiddler for a long time (from v1 days) and have had many versions installed. Today, there was an update and during update it stopped saying that it couldn't uninstall the existing version from C:\Program Files (x86)\Fiddler2 and aborted. So, I tried to manually uninstall from Windows 10 Add/Remove as well as by going to the mentioned folder. Fiddler is not present in either (there's no Fiddler2 folder at in Program files folder).

So, I tried the following:

1. Downloaded and installed Fiddler to C:\Program files...

2. Installing to default App Data path

3. Deleting all references to Fiddler from registry and installing

Regardless of what I do, the error when running Fiddler is the same:
---------------------------
Machine-wide installation has been found. Progress Telerik Fiddler is closing now.
---------------------------
Machine-wide Progress Telerik Fiddler installation has been found at C:\Program Files (x86)\Fiddler2\ . Please, use that one or uninstall it before starting the per user Fiddler installation.

 

How do I get around this?

[Urbain]

hello

i got the same problem.

i don't have the solution to install fiddler 4 but you can uninstall fiddler 4 and go back to fiddler 2

 

and it's work

[Bart]

Hi I am encountering the same problem. Tried to uninstall  and install again, but problem keeps appearing. Is there any workaround / solution for this?

[Simeon]

Hello,

Sorry about the late reply. In order to reproduce the problem, I need to know from which version of Fiddler you were trying to update to the current one.

I also need to know which Windows version you use. Could you, please, also tell me if your account has administrative privileges. I am also interested to know if the installer requested for administrative credentials and if you provided some.

You could try to fix the problem by removing the "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Fiddler2" registry key with all of its subkeys. Please, note that this key is in the "HKEY_LOCAL_MACHINE" root key. If the following registry key is present, delete it as well: "HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\Microsoft\Fiddler2"

Please, let me know if this solves the problem.

 

Regards,

Progress Telerik

[Sameera]

Thanks. Removing the Registry Key worked.

[James]

I know this is an old post but for the sake of future readers. The solution suggested by Simeon, to remove the registry keys, resolved the error for me as well.

[Kadir]

kadir

[Grant]

it worked for me as well in 2020 - time to update the fiddler4 installer to do it?

[Eric R | Senior Technical Support Engineer]

Hi Grant,

Thank you for the feedback. Currently, the Fiddler Installer does check for the existence of the older registry keys.

We implemented this once we changed the installation directory from Program Files to the User folder. However, there are some cases where it will require manual removal. 

Please let me know if you need any additional information. Thank you.

Regards,

Eric R | Senior Technical Support Engineer
Progress Telerik