How to determine the cause of slow thunderbird in windows 8?

Question

Mozilla Thunderbird

In general, the mail client from Mozilla is stupid in the most merciless way at startup, and so, by the way. 2-3 minutes may pass before it becomes adequate for work. I would like to know what tool can be used to determine what the brakes are. Something similar to procexplorer from Russinovich but in addition would show the timings of the request to a particular thread or process in the system.
To enumerate the options offered from the top Google search from the series - reinstall the client, index the database, and the like after using Linux, frankly, too lazy, I want to immediately get to the bottom of the truth.

Answer 1

a couple of disk defragmentations, cleaning the registry, updating the mail client itself and the relevance of the issue has been removed