I never recommend archiving and you should always go Tools to Options, find the Archive and remove the check for the automatic part. If you must archive, you can easily do it manually through the File menu.
First, I would create a Personal Folder File (through the File to New menu) and give it a general but good name. You can keep this open all the time. Then create a new folder named anything, maybe ?Old Stuff?. Then manually drag and drop emails to that folder in the folder list to move them. This will take them off of your Exchange server and put them on your local hard drive. Now, go search your system for all archives and other Personal Folder Files.
Choose ? Start ? Find ? Files or Folders, put *.pst in the named box and verify that the C drive is selected for look in. and Search. You need to note ALL of the pst files and open each one manually, be sure to note the location (path). Once you noted all of them, you can go back to Outlook and choose File ? Open ?Personal file and open EACH ONE. I would manually move all of the emails at once from the archive to that Old Stuff folder mentioned above. This way you will have one location for all Old Stuff and it can be kept open all of the time.
If you are not going to open all of the archives as you are looking for something specific, you may know about the date it was archived. When doing the file search note any with dates around the same time and finding it will be easier.
Be sure to close all of the archives when finished.
Good luck,
Steve