Well, hello.

I reinstalled my computer two days ago, and since then, Opera is completely fucked up. I lost some of my most recent bookmarks and the whole config. I did make a save (just copy/paste of the appdata Opera folder, but still...), but nothing seems to be usable with the new fresh install I did.
But that isn't the biggest issue : flash is worth.

The first problem I had was that I could alt-tab without minimizing the fullscreen on youtube, which is pissing me off a lot. I found a fix, deactivating the pepperflash thing in the flags. Works, but causes the Flash Player plugin to not to be detected anymore..., which means that youtube flash videos are using a player where there is just the 720 and 360p options, and the rest of the web tell my to install Flash Player, which is of course done, downloaded from the Adobe Website, compatible for Opera.
The HTML5 player is now working on youtube, which is nice since I didn't find any way to make it work on my previous installation (and I'm still on the same Opera version !). Bonus question : space bar to pause/read video on youtube doesn't work with the html5 player, any fix ?

Then, last issue : Opera isn't detected as my default browser. Every single time I start Opera, I'm ask the question "Do you want Opera to be your default browser blablabla". Every. Single. Time. The thing is, Opera isn't even detected as a browser in the "chose your default programs" of Windows.

So that's it for the moment, more stuff will probably come over in the next hours of use...
Keep in mind that I've already googled a lot of my problems to try things out, but nothing worked (and the few things that worked destroyed others...).

Windows 7 SP1 64bits, Opera 26.0.1656.60 Stable.