Bishybarnybee
Bronze Level Poster
Hi Androcles - I would take this article with a pinch of salt.
From reading the article I suspect he is talking about problems caused by moving the Program Files and other system files to the data drive in a way that Microsoft do not support (and which I reckon would be a recipe for disaster so not surprised Windows would object)
I only moved the User data folders (Documents, Pictures, Music, Videos etc.) using the Microsoft supported route via each folder's Properties -> Location -> Move route as we have some large HD Video footage files as well as .wav music files and loads of hi res Photos/Raw image files and I don't want them clogging up the SSD. I also moved the Windows Swap file to the data drive (again using the OS supported method). I left all the main System files, Program files and the App Data folder on the SSD OS drive.
All the folders moved OK under Win 8 and I upgraded with this configuration. They are still in place and accessible following a relatively smooth upgrade to 8.1 (which also gave me the option to move my SkyDrive to the data drive - functionality not available in Win 8)
All subsequent post-upgrade updates from Microsoft seem to have downloaded and installed with no major issues.