OK, question here that hopefully someone can answer. I am looking to go to Win 10, but be fore I do, I need to decide on clean or upgrade. I have 120 GB SSD for my primary system file, but some other programs that do not give you a choice of the installation path are also on the same drive. That dive only has 22 GB free, which concerns, me so I might want to get a bigger SSD for my system. Anyway, there is a sub folder in the Windows folder called "winsxs" which is where Windows keep a bunch of file every time that you do a Windows update. From what I know, you cannot delete any files from that folder, so it continues to grow over time and the only way to reduce the size of it is to do a new install.
Does anyone know if the winsxs folder is needed with Win10, and if someone has upgraded and has a winsxss folder, can you post here how many GB yours is?