All my personal files (pictures and documents) were left undisturbed, but most of my additional tools like Adobe Reader, AVG TuneUp, Chrome, Firestorm, GeForce Experience, Kaspersky Total Security, iTunes, Malwarebytes Anti-Malware, Skype and Quicktime were lost. This was possibly due to those apps being set to a different language (American English) than my computer is (Swedish), it could also be because they weren't - and still aren't (as I found out when I tried to reinstall some of them again (Kaspersky and GeForce Experience) - compatible with Windows 10.
My biggest concern initially was the loss of all my browser bookmarks, however they all miraculously returned to me today, once I had logged into my Google account. With the returning bookmarks I also got all my saved passwords in Chrome back.
I have reinstalled AVG TuneUp, Firestorm, iTunes and Skype, but - as I said above -