Hi @tefurto777 ,
welcome to the arduino-forum.
I'm pretty sure that you agree and will follow the way how to solve your problem mimimum 200 minutes faster.
This requires to invest 20 minutes of your precious time to read how to speedup solving your problems.
Directly after registering you got presented informations how to speed up solving your problem.
You should really read it.
This is the important part.
You specified COM3 as the comport but the uploader was unable to open this com-port
possible reasons:
-
wrong comport number = com3 does not exist at all
=> choose the correct COM-port -
you are using a USB-cable that is only for charging and not for datatransfer
=> try a different USB-cable -
you haven't installed the correct driver for the USB-to-TTL-converter
=> tell us what exact type of microcontroller you are using including pictures of both sides of your microcontroller-board -
you have chosen the wrong device for uploading
=> post screenshots how you have adjusted the arduino-IDE
You will have to provide much more information to analyse the problem