Make sure you are accessing the correct pst. Go to file-open outlook data file and see if the backup of the pst is there. If you changed domains, it is likely when you logged into the new domain you also created a new profile on the PC. If that is the case you need to move the old pst into the new windows profile. Do a search including hidden files and folders for your .pst file. Move it into the same folder in the new profile. If that is not the case, please provide more details about what you mean by migrating to a new domain. Thanks!