I am amazed it took so long for us to know what the purpose of Opera Browser Assistant is and that nobody from the company actually stepped in to explain what it does. Although since it seems to be related to tracking, surreptitiously installed and there's no switch for it in the browser settings I'm not surprised.
I wonder, what is wrong with giving users a choice and being transparent? I take it they'd want to have more market share, but I bet disregarding users does the opposite. And not only this business of the Browser Assistant, the constant pushing of Opera GX and icons in the sidebar (even though you have chosen not to be shown those messages again) or the removal of privacy oriented features (e.g. Do Not Track) doesn't help either.
Aaaaanyway, I digress, I came to find out what the thing was and now that I know more or less what it's about I decided to block it. I'd rather have a native option to opt-out of the assistant, but there are several options when you want to prevent program executions without 3rd party software:
- What @burnout426 said, either via GPOs for those using Windows Pro+ or through that registry key; but that way the blockage applies to programs started from Explorer, I don't know if it'd work for the assistant.
- Blocking access to the path where the program is through the permission settings, you could remove the writing or execution permission from "C:\Program Files\Opera\assistant" or the executables that are in there; but if the browser or the installer relies on having access to those locations in this case may through errors.
- Use AppLocker or Windows Defender Application Control to define rules to block it, but that's not for everyone.
I will be circumventing its execution more or less (because anything running as admin could deter it) instead of blocking it making use of a mechanism Windows has to debug applications. Knowing the program names all that needs to be done is create a registry entry at HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options and set a Debugger value pointing somewhere else.
Since we want to block the assistant it should look like this (I'm also adding one for assistant_installer.exe for good measure):
After that it wouldn't matter if the assistant were set to execute on boot, whatever program you put in there would be executed instead. There are a couple of caveats:
- The Opera installer, if run with admin privileges, could check that key and delete it...
- And if it does, depending on what you choose to run instead, you may not know realize the assistant is running again.
- It blocks any program with that name regardless of where it is, so if you had another program with the same name it would also be blocked.
- Just like with the option to block access via permissions, if the installer or the browser itself expects the assistant to do something it may throw errors.
I'm uploading a registry file for easy use, along with some instructions and the program I'll be running instead (along with its source). It's a dummy program, it does nothing except returning the value 0 to whomever executed it because it's the usual return value for when things go according to plan, just in case.
Here it is: Dummy exe for Opera Assistant