However, if you still cannot make the official Opera portable | Opera.com or the unofficial Opera Portable | PortableApps.com the default browser on your USB and would like to install the official Opera on your computer, please get it from here: Opera | Opera.com.
You can also install the official Opera | Opera.com and the unofficial Opera Portable | PortableApps.com on your computer. Still, you cannot install the official Opera | Opera.com and the official Opera portable | Opera.com alongside each other on your computer.
The rationale for the above is that, in my experience as a web browser enthusiast, I have tried to install the official Opera | Opera.com and the official Opera portable | Opera.com alongside each other on my desktop-only computer, but then, I discovered the following:
Upon installing the official Opera | Opera.com and the official Opera portable | Opera.com, the official Opera portable | Opera.com automatically replaced the official Opera | Opera.com, and this is by design from the Opera browsers' developers, and cannot be overruled.
However, just for the record, if you would like to use two variants of the Opera browser on your computer, you will need to use the official Opera | Opera.com and the unofficial Opera Portable | PortableApps.com, upon which these browsers will work properly together.
Nonetheless, I would NOT recommend running the official Opera portable | Opera.com and the unofficial Opera Portable | PortableApps.com simultaneously because that might cause a compatibility issue. But anyway, I have NOT tried to do so myself, so this is just a heads-up.
I would like to emphasize that, unlike the official Opera | Opera.com, which does update itself automatically, the unofficial Opera Portable | PortableApps.com does NOT update itself automatically, and this is also by design, so every time a new version is published:
If you want to keep it continuously updated, you will need to reinstall the unofficial Opera Portable | PortableApps.com on top of the previous version, which might sound somewhat weird, but I can confirm that this works quite well on my computer, so it is also worth remembering.
But anyway, hopefully, you will enjoy using the unofficial Opera Portable | PortableApps.com on your USB or the official Opera | Opera.com and the unofficial Opera Portable | PortableApps.com on your computer because I use these browsers and many other ones.
Good luck!
Microsoft Windows 10 Professional 64-bit V. 22H2 (19045) Retail Desktop PC, EAMH Paid/EEK, MB 4 Prem., and Unchecky, MDFW, FF with uBO/AG, Grammarly Free, MBBG, and Acronis CPHOE (DI), RuckZuck, PatchMyPC, UpdateHub, WingetUI, UCheck, and Winget. I have 29 Years of PC Experience.