I also switched from W7 to W10 and had the same issue with 'read-only.' Murray, If you decide to pursue this beyond the Desktop workaround that you are currently employing then I suggest these steps. Note that if the first or second step fixes it then there is no need to proceed any further.
I appreciate that steps 1 & 2 are technical procedures that you might not normally use. They can be done, however, even without knowing about the complexities of the permissions schemes involved. Just read each stage and complete it before proceeding to the next. 1 Use the procedure given in the MS Knowledge Base article that Doug gave a link to above - This article was written for MS Office 2013. Doug, The linked thread has been rewritten.
I have managed to make Microsoft Office 2007 Portable using the Thinstall package. However, there are several issues with this: - Clip Art, as useless as it is, doesn't work. - If you don't know what your doing, Thinstall will by default, write values to the Application Data directory.
I have therefore rewritten my earlier post above. In doing so I have taken the opportunity to explain that I would not use CCleaner - I appreciate that Figment has only suggested using its temporary file cleaning facility but it could so easily be misused once installed. I wrote my earlier post because Murray, the OP, reported that he was using a workaround instead of fixing the problem.
Try.3 - a user Dell Inspirons 7779, 1545, 9300; Windows 10 Home x64 & Pro x86; Office Pro 2007; HP DJ2540; HTC UPlay Android 6.0, MyPhoneExplorer.