when I said check permissions have you right clicked the file gone to properties and under the security tab checked your username has all the permissions in the tick boxes ?
or have you tried finding the outlook .pst file path in data file management then closing outlook and replacing the file manually with a copy of yours then reopening outlook ?
be warned this might destroy what you have so more backups of the files might be advisory
other than that maybe the key to this is the fact it thinks it's a fresh install everytime it's loaded, have you tried a fresh install of outlook ?
did you install win7 as a fresh install or was it an upgrade on vista ?