You can always download the last Opera Stable from the right side of https://blogs.opera.com/desktop/. Then, launch the installer, click "options", set "install path" to a folder on your desktop, set "install for" to "standalone installation" and install. That way, you can test that version without affecting your regular Opera. If everything is fine, you can launch the installer again, set "install path" to your normal Opera location and choose to upgrade your normal Opera. Then, when you're done testing with the standalone installation, you can delete it.
Download the x64 setup from ftp://ftp.opera.com/pub/opera/desktop/51.0.2830.40/win/, launch it, click "options", set "install path" to "C:\Program Files\Opera" (not "C:\Program Files (x86)\Opera"), set "install for" to "all users", check "Make Opera default browser", set the bookmarks import option to what you want and install. You can then delete "C:\Program Files (x86)\Opera".
If you don't need to save anything in your OPera profile, before you install, you can delete "C:\Users\yourusername\AppData\Roaming\Opera Software\Opera Stable" and "C:\Users\yourusername\appData\Local\Opera Software\Opera Stable".
That should fix the registry settings for Opera so that it shows up in Default Programs. If it doesn't, you might have to wait till Opera 52 comes out or go through the registry yourself and see what's wrong.
When Opera starts up, you can go to opera://components in the address field and click "update" for Widevine if you want to makre sure you have the newest so Amazon Prime works right.
@haleba said in Unable to set Opera 50 as the Default Browser (Win8.1):
Profile Guided Optimization
This is a compiler option to run and test a built Opera and then recompile it to be faster in certain areas. It is unlikely that those optimizations introduced a bug in Opera reading and writing of its (and or the installer's) registry settings. So, I wouldn't worry about that.
After the clean Guest profile pretty much ruled out internal issues I went to the site's tech support forum and sure enough there was a whole thread of complaints about sessions being terminated on logout.
The problem was finally resolved today.
Opera has so many quirky little problems it's easy to suspect it as the problem causer.
On the positive side, using the pristine profiles in my Windows Guest account is great new tool to help isolate issues with both Opera and Chrome.
Thanks again for the help.
Your question prompted me to consider my Opera installation. Disabling extensions had no effect, but it made me think about the fact that all my post-Opera 12 installations were being installed in a single directory dating back to Opera 32, so I installed Opera 39 in a "Opera39" directory and now I'm mangle-free.
Going forward I'll install new major versions in version-specific folders.
Version 40? Yes, because there's an ongoing unresolved severe memory leak issue reported for versions after Opera 40. I've noticed a mild leakage problem with the older versions I'm using where Opera will consume substantially larger amounts of RAM when left open for several days. This is probably an issue with the Chromium engine since Chrome also gobbles RAM as well if left open.
Given Opera's quirkiness, this mangled rendering issue being a prime example, I'm holding off on a fully current update until I see a resolution.
Thanks for the input.
Looks like my waiting game paid off. I stuck with old reliable v. 12 until the whole bookmarks madness was worked out. Less than 2% of the browser market share and Opera drops their bookmarks management when none of the guys kicking their butt was doing likewise! This is the kind of out-of-box thinking that made Opera so distinct--no one else is using the type of tools integration Opera has (had?)--but they severely shot themselves in the foot this time.
This is my feeling exactly.