I`ve read a lot of stuff about recovering email data from one end to another here but I don`t get it. What to do in my case...

First my Windows XP crashed. All I could do was to save data and format the pc. Now Im on a new computer with Windows Vista, installed Zimbra and it works as before for my pop mail account (and I use only that.) What I could save is the whole zdesktop folder, I also found i guess what are the messages: msg-files in the store-folder. How can I get these old messages into zimbra again? When I tried the way with renaming some of the msg-files to eml they where empty: emails with no sender or text...?

Please explain it to me as a "dummy" in IT , is there a way not to go a long way around and/or not to handle every single email (since I don`t know from the unreproducible numbering if it`s an important or unimportant mail...)?