I suspect it's Magix advertsing as actually @Kazem-Mirahmadi hasn't removed everything Magix. See if the below thread helps. It's from the Magix Community forum not this Vegas forum but is relevant. The same problem has been posted here but I couldn't find the threads.

https://www.magix.info/us/forum/pop-up-message-when-booting-up-pc--1306731/

Thank you all, there was an app "Update Notifier" I removed that now it seems I don't have this problem anymore,

There is also a "Stay Informed of .." option In the "Options> Preferences> General" menu, that can be disabled. The infamous "Update Notifier" (typically installed along with Sound Forge), is usually the main cause of pop-up aggravations.

okay, same problem, it's still there😑😑

it's like a virus.

the thing is that I don't have any of their products installed on my PC, and yet I can't find a way to get rid of this pop-up,

If you go to your MAGIX My Account, you can turn off MAGIX emails by unchecking the subscription checkbox under the 'Info Service' listing; however, I'm not sure if this affects pop-ups or not.

Also, check the 'Startup Apps' and 'Services' lists in the Task Manager (Ctrl-Alt-Del) to see if there is a MAGIX entry there that might cuase pop-up alerts. If there is something there, try disabling it and see if that ends the pop-ups.

You can most likely block msedgewebview2.exe in your firewall to stop it if all else fails. I think Vegas is responsible for me seeing it all the time in logs

I'll go to try these, 🙏

Well, I don't see anything here I guess,

The only suspicious member of this club and I couldn't find him in my apps & features, But as you see he exists in my task manager,

😕 I'm not sure!

If you go to your MAGIX My Account, you can turn off MAGIX emails by unchecking the subscription checkbox under the 'Info Service' listing; however, I'm not sure if this affects pop-ups or not.

Also, check the 'Startup Apps' and 'Services' lists in the Task Manager (Ctrl-Alt-Del) to see if there is a MAGIX entry there that might cuase pop-up alerts. If there is something there, try disabling it and see if that ends the pop-ups.

I checked it, I wasn't a subscriber there

 I'm not sure!

It could well be the cause of the pop-ups. A Google search of 'UpdateChecker.exe' mostly results in it being classed as Malware. In your screenshot, it shows as being 'enabled'. You should be able to disable it by R clicking on 'enable' and selecting 'disable'. I'd be cautious about blindly following uninstall instructions from unknown sources on the internet as that may only introduce other unwanted problems.