What is uploading?

If TCPview doesn't show anything, this probably won't either. But it never hurts to try:

Resource Monitor

Type 'Performance monitor' in start menu search box and open that, you will find a button 'Open resource monitor'.
In resource monitor you can see the network usage per process on the last tab.

Cheers!

Edit: Ah, they were faster than me :P

I find Process Hacker useful for this type of investigation Overview - Process Hacker

Totally free open source application, partly written by a former Mod here

Funny you mentioned Comodo, I have used it for years on many systems My own and clients, It actually has a very similar option to show network activity, though of course it's overkill for just that - If its a new install it was probably downloading definitions for problem web addresses - you can normally edit the preferences for what and when it downloads - It's a very complex program to set up at times but the protection it's capable of is worth it (In My Opinion, of course YMMV ).

Process Hacker is like Task Manager on Steroids - the fact that it can simply break out some of the contents of windows combined processes is worth the install, I think it's possible to set it to replace Task manager as the default which for someone interested in the inner workings of the OS can be a help (you can always run Task Manager from within Process Hacker )

FYI, Process Explorer has on option to replace Task Manager + options to check all running processes on VirusTotal.
I'm satisfied with that program so I've never checked out Process Hacker and therefor can't compare them.

Process Explorer

The full Sysinternals Suite is part of my basic install - gets loaded on every system I setup, It's been an essential for me since long before Mark Russinovich & Bryce Cogswell became part of Microsoft.

The Autoruns App is essential to diagnose startup issues and the other utilities are probably the best in class