Thank you. Windows 10 went good so far, I also have a 64 bit computer. I'm having some minor problems but nothing unusual for a new OS, so far at least.
However, I kept having the manifest error. Then I reinstalled Visual Studio (which caused a lot of problems of its own and took quite a while, but that is not unusual as well), and even with the fresh VS I still kept having the manifest error.
Then, my husband (he knows quite some more than me about coding) took a look at my manifest's code and tried removing some quotes I had in the description text in my Consturct2 project description: that fixed it. Seems that when you put text in quotes in there, the fist quote closes something that goes in quotes in the code itself and it breaks.
I hope this might help someone else, until the Construct2 developers can fix it.
Now, I finally submitted my app to Windows and I[m waiting to see if it is approved or more problems come up. Usually it is approved within a couple of hours, and is been quite some hours this time and is still being reviewed.