[quote user="Jim Adney"]Problems Migrating Pegasus from XP to Win 10[/quote]
This was a single-user version of Pegasus v4.72.
Okay, with Brian's hint about the protected nature of the Windows program files, I've managed to solve my problem. Here's what I did:
I installed Win 10 on my "new" PC and re-partitioned to give myself separate partitions for OS, applications, page file, and home directories.
Created 3 directories in D:, Program Files, Program Files (x86), and OldApps (for Pegasus, among others.)
Installed a fresh copy of Pegasus v4.72 into D:\OldApps\Internet\Pmail, but did NOT do any network setup.
Opened the new Pegasus and moved the mostly empty mailbox to the location where I wanted it.
Went to my old PC and created a new mail folder into which I transferred ALL my New Mail. That put all my mail into one path/directory.
Copied the entire contents of that directory onto a thumb drive.
On the new PC, I deleted the contents of the (moved) mailbox and replaced it with the contents from the thumb drive.
When I opened Pegasus on the Win 10 PC all my mail was there, but now I had to transfer the "new mail" from its folder to New Mail.
Transferring to New Mail was difficult because there were 3600 messages there, so Pegasus claimed to run out of room after several hundred messages. I got around this by closing the folder I was transferring from and re-opening it. Then I could transfer more. I had to repeat this several times, but each time I did this, more transfers were allowed. I've now gone back and cleaned out about half of those messages.
With the transfers complete, I found that everything I needed was there, except my various Identities. When I started to replace them, I found that this was easier than expected because all the POP3 and SMPT info was still there. So setting up all my identities was just a matter of creating Identity names and selecting POP3 and SMTP servers for each one.
thanks for the help, Brian.