Can you explain how you set about "changing the server from pop to imap"? I think a necessary step may be undoing this change.

If the account formerly used POP then its messages were stored on your local hard disk and you won't find them on the server, which is where IMAP will go looking for them. :-(

I went into Tools, Account and the Server settings to change it to imap. It is now switched back to POP but the subfolders still aren't showing up.

I wish the settings page wouldn't let people do that. There are two distinct modules, one for POP and another for IMAP and neither can do the other one's job. Just changing the settings doesn't automatically switch to the other module.

Did just the subfolders vanish? You still have the address book? It didn't ask to to set up an account is if it was starting up from fresh?

I'd like to see a file listing of the part of your profile that stores your messages - this might tell us if any files or folders have become orphaned. I do suspect that AVG has caused some damage.

What I would do is find the profile, open the Mail subfolder and open a command window. Then i'd use

dir /s /b > c:\listing.txt

and examine the new file just created, c:\listing.txt

Only the Inbox subfolders vanished. I still have both address books and all my messages in the regular Inbox folder. How do I find the profile?

I finally found the Mail folder you spoke of, but when I opened the Command Prompt window and typed in the command, it denied access. Is there supposed to be a space between dir and /s and between /b> and c:\listing.text? It's been a long time since I've used DOS.

Under Mail, I found Inbox and within it are all my missing subfolders.