Can Fiddler remove the proxy setting in Windows10 PC?

[Yamato]

I'd like someone to help to resolve the issue about proxy setting in Windows10.

Fiddler Version: Progress Telerik Fiddler Classic v5.0.20211.51073
Client PC: Windows 10

I installed "Fiddler Classic v5" into about 300 client PCs (Windows10).
When Fiddler is running in PC, everything is going OK.
Howerver, when Fiddler is disabled/stopped then enabled/started, the proxy setting in PC might have been gone.
I'm wondering if there might be some bugs in Fiddler?

I'd really appreciate it if someone would help to answer this!

Regards,
Yamato

[Nick Iliev]

Hello Yamato,

 

 

Please be aware that Fiddler Classic is no longer in active development and offers no commitments for releases, patches, or technical support. By using this product, you assume all associated risks. We recommend upgrading to Fiddler Everywhere. The above is officially stated on the Fiddler Classic product page.

That said, the Fiddler Classic will always try to automatically unset the operating system proxy settings and revert them to their original values. An issue could only occur in some corner cases where the application stops abruptly and, as a result, is unable to clean its own proxy settings correctly set on Windows.

Note that the previously mentioned Fiddler Everywhere has a more advanced mechanism for clearing the proxy, so you might want to try it — this way, you can also determine whether the issue is strictly related to Fiddler Classic or if it's due to some third-party software (e.g., security tools or policies). Fiddler Everywhere also offers verbose application logs, which can be helpful in investigating a potential issue related to proxy settings.

 

 

Regards,
Nick Iliev
Progress Telerik