There is an account called "Administrator" and it is disabled by default.
If you had enabled it in Windows 7 then it could well be reset back to its default [disabled] by the upgrade and it would therefore not appear in the list of accounts in
Control panel, User accounts or when logging on- so leave it disabled.
Your own account is in the group called Administrators but only that one special account has the
user name
"Administrator". If this is the case here then there is no account problem as such.
The account with the user name "Administrator" is the "Built-In Admin" / "Default Admin" account. It operates by default without the protection of UAC. It is intended to be disabled normally but should appear
automatically in Safe mode if, and only if, Windows detects that there are no other functional Admin-level accounts. It is worth minimising its use because if it ever suffers user profile corruption then you would have to reinstall Windows to fix it [and
that is a big job].
I do suggest, therefore, that you create one or two additional password-protected Admin-level accounts before doing anything else and then make Password Reset Disks for them as well as for your own account. If you were to suffer user profile corruption
in your own account then you could use one of the new Admin accounts to help you fix things [without a functional Admin-level account you would find it difficult to recover your computer from a crisis].
I suggest these fixes for the read-only problem. Note that if the first or second fix solves it then there is no need to proceed any further. .
I appreciate that fixes 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.
Fix 1 Use the procedure given in the MS Knowledge Base article at Error opening Office documents after upgrading to Windows 10 This article was written for MS Office 2013.
1.1 For MS Office 2010, check in Windows explorer for the correct folder path to use in its Workaround 1 para 1 command
icacls "%programfiles%\Microsoft Office 15" /grant *S-1-15-2-1:(OI)(CI)RX
1.2 For MS Office 2007, its Workaround 1 para 1 command icacls "%programfiles%\Microsoft Office 15" /grant *S-1-15-2-1:(OI)(CI)RX
needs to be changed to
[for computers running 32 bit Windows 10]
icacls "%programfiles%\Microsoft Office" /grant *S-1-15-2-1:(OI)(CI)RX
or [for computers running 64 bit Windows 10]
icacls "%programfiles(x86)%\Microsoft Office" /grant *S-1-15-2-1:(OI)(CI)RX
or [for those rare cases of 64 bit MS Office 2007 in either type of Windows 10]
icacls "%programfiles%\Microsoft Office" /grant *S-1-15-2-1:(OI)(CI)RX
Fix 2.1 In preparation for this fix, disable OneDrive in Task manager, Startup tab and restart the computer for this change to take effect.
2.2 Then use the augmented permissions resetting procedure provided by another user, an MVP for Outlook, in Fix read-only access
to Office files.
2.3 Whilst the procedure was written with Outlook in mind, it applies to write permissions for all the documents etc folders - start from its sub-heading
Resetting all permissions for your user account.
2.4 One essential component of the procedure is in its para 6 - Replace all child object permissions entries with inheritable permission entries from this object because omission of that step fatally undermines the fix being attempted.
2.5 If you subsequently use OneDrive [by, for example, opening an Office document from a OneDrive folder], check folder permissions again as some users have reported that the problem returned when doing so. If this happens then you can try repeating fix
2 or moving on to fix 3 below.
Fix 3.1 If the fault persists, reappears after a system restart or reappears after re-enabling OneDrive use the further procedure created by the user Figment in \[BUG\]
Windows 10 OneDrive @ Default Settings Causing Major ...
3.2 You will see references in that thread to using the "Default" ["Built-In"] Admin account if mistakes are made during fixing with the result that "permissions" are set so badly that further remedial action is inhibited. That's fine but it is much safer
to create two additional password-protected local Admin accounts beforehand instead and to make a "password reset disk" for each of them. By avoiding use of the Built-In admin account as much as possible, the chances of this special & irreparable account
suffering user profile corruption are minimised so that it ought to remain fully functional & ready for a day when there might be no alternatives left. Having two additional password-protected local Admin accounts ready is not just a precaution for this read-only
problem, it is a precaution that all users ought to take as soon as they have installed Windows.
3.3 The standard precaution of making an up to date system image beforehand also applies. As does booting from your Recovery drive first just to make sure that it works and that it will therefore be available to enable restoring from that system image should
the need arise.
3.4 Personally, I do not agree with using the tool Figment suggests [CCleaner] even just to clean up files. Windows has a perfectly satisfactory & safe tool for doing that [in File explorer, right-click on a drive, select properties then Disk cleanup].
CCleaner can do this job but some say it is not safe even for this limited use; moreover, it has a Registry cleaning mode that is definitely dangerous as it can seriously & irreversibly corrupt the Registry.