Hi there, im using version 1.3.4 for windows 10 and just saw that i can update. Im using the sw for specific files so really never checked for updates. My bad 
I want to update to 1.4.15 . Normally all my updates are done automatically. Now its not. I downloaded the latest version and want to execute the file. I dont understand why it askes where to install it. Will it overwrite the old version when i select the that folder? Sorry for the noob question.
Yes, it overwrites the old version.
The reason why it doesn’t recognize the already existing installation is, that we had to change the unique installation id. Another side effect of this change is that you will keep seeing the 1.3.4 under Windows’s “Programs and Features” list. Sorry for this! Will not happen again. 
See the described workaround in the linked issue.