windows search for emails?

Hello,

I am struggling to use the windows search function for emails within Thunderbird's mbox files. The windows search function simply doesn't work with TBP.

In the settings of Thunderbird, there is a button that will allow the windows search function to search within emails, as well. I can check the checkbox, but after I restarted TBP, the checkmark is gone. I have tried this in Windows 7 and Windows 10, with various TBP versions down to v24... and always had the same issue.

I suspect that this has something to do with the modifications done to TBP to limit the read/write access if installed on a thumb drive. In the comments on portableapps.com it says that the auto check for default mail client has been disabled and changes within the registry (to enable TBP as the default mail client) will be deleted when TBP is closed. Within TB, these two settings (default mail client and enable serach function) seem to be closely linked in one menu.

Does anyone have any clue on how to solve this issue?

Regards,

Boris