I copied them to a folder and tried to open the most recent (prior to
the new PC) but got the error message "File access is denied. You do
not have the permission required to access the file N:\OUTLOOK
FILES\archive.pst"

It made no difference which file I tried to open, I got the same
related message. The files are mine, on a PC only used by me and
belonging to me. What permission do I need?

Also verify the pst itself isn't marked read-only.

--
f.h.
Microsoft Outlook MVP