I'm having a problem backing up Outlook in that every time I try to utilize the backup function, it gets halfway through and locks up my machine. I've managed to export the .pst file, but the file size is considerably smaller than the actual file on my machine, so I'm suspecting that all is not right with the exported version. Does Outlook compress files when exported? I'm running Vista and Outlook 2007 on a Dell machine. Dell is suspecting an OS error, and wants to reformat/reinstall, hance the urgency to copy Outlook. Any suggestions?