The files on the flash drive when opened do not say read only when opened direct from that drive. Its when the files are saved to another folder that the problems start.
Do all folders in Windows have 'Read only' as their properties. Because all my folders on this computer do.
What I have just done on the other computer is this......
I copied the Excel files concerned, from their folder in Program files, and saved them to the folder on the left called 'Downloads' (Windows 7 OS). During their copying across, a message box appeared, saying 'converting files'. The icons are now slightly different. I can now open these files from that location, and they do not say Read only. I am loathe to copy these files onto the flash drive in case of contamination.
I have now copied the backup files direct from the flash drive to this Downloads folder, and the icons are standard Excel icons, and they open as they should. No Read only in the title.
BTW, I am using Office 2003 with 2007 upgrades. Could not get on with the 2013 version, so went back to this version, which normally is superb for me.