Where can I download the old version 3.6.12 64-bit wireshark

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Recently, I found I have old version 3.6.12 64-bit wireshark in my laptop installed program list, but the folder is gone. I also have 4.0 installed. So now, I have two versions of wireshark in program list.... normally, when update to new version, it will ask to uninstall the old version, could be something left in. As I can't uninstall (it says no unintall.exe), I would like to try a new install of 3.6.12 64-bit wireshark, and then uninstall again. However, I could not download the old version 3.6.12. Could anyone tell me the place to download 3.6.12? Much appreciate!