Error 1603 when installing and updating Studio 2015 / 2015 SR2 after Windows 10 migration

Hi everyone,

I'm dealing with a big issue when trying to install and/or update my version of SDL Trados Studio 2015, and I hope someone can help me resolve it.

Everything started when SDL Trados 2015 SR2 became available. I downloaded the updates from my account, and proceeded to install them as usual.
Unfortunately, the installation can't go through, displaying a "Could not find network location TT" error message.
All I can do then is abort the installation, which shows a 1603 error message.

I have kept working with my standard version, but since I had some free time a couple of days ago, I decided to give this another try.
As per instructions found in the SDL KB, I thought uninstalling my current version of Trados would help.
Except it really DIDN'T, and I received the same error messages when I tried to reinstall it.
So I was left with no software at all...

I have tried several "turnarounds" from the knowledge base, but none really helped with my case.

In the end, I was somehow able to manually reinstall the standard (as in non updated) version of Studio 2015, using the tips from this KB producthelp.sdl.com/.../9136.html (I had to run the individual MSI files as administrator first, by adding the related command in the Windows registry).

I am now back to square one, using the non updated version of Trados 2015.
The problem is I'm not sure my manual installation will be stable over time, and I can't update the softwares I paid for.
(I haven't tried updating Multiterm, but I'm afraid the results will be the same).

Perhaps this is important to mention I have recently migrated from Windows 7 to Windows 10, since this seems to be a MSI/Windows installer problem.
Although, this is the only software I had trouble with since migrating.

Has anyone been confronted to this issue?

Thanks for your help,
Flavien