If you can find the old Outlook Express folder inside of the old Program Files - great. Copy everything there and paste it into the new Outlook Express; there will be some grumbling about overwriting - do it. That'll bring back your address book.
The mail is another matter. That folder has a Registry type name - very long & alphanumeric. It's the Store folder which can be accessed under Tools - Options - Maintenance. I doubt if you ever looked; right?
Well, all the mail folders have a .dbx extension. Perhaps a Search will uncover them in the old location. If you locate them, you can go to File - Import - Messages (in the new OE) and bring them in. Those you can't just copy into the OE folder.
Actually you can copy the .dbx files. Start OE but don't add an email account. Find all the .dbx files on your old hard drive. Locate the folder with the .dbx files on your new hard drive and replace those with the old files. I do it all the time.