Sorry but are you telling us you don't backup and restore such things?
As to the upgrade problem I see that a lot. Now that I've done it a dozen times it's very unpopular what I discovered. That is, "works fine for me." So in a dozen times, it went off without a hitch on our laptops but something is amiss on the owner's PC.
What I'm encountering are folk that demand Samsung fix their PC when this happens. I'm unsure how this will play out since as we are well past the years where folk were expected to troubleshoot Windows and we now expect these things to just work.
I have windows and the GS3 phone. My carrier is AT&T and I'm trying to upgrade my firmware on my phone. ATT only allows you to do so by connecting the phone to the computer and using Kies.
When I connect my device and begin upgrading, it prepares to download the upgrade and then, due to settings, my computer asks for permission to actually begin downloading. I say yes, Kies turns grey (like when there is a pop up that you have to close) and nothing happens.
I've talked to samsung live chat, and called them. they couldn't resolve the issue. I'm pretty much left with having to take the phone to ATT and having them do it, which would wipe everything on my phone.