Importing a .pst file into outlook 2003

Hi, I was wondering if anyone could help me, I created a .pst file a while back knowing that in the emails was important data i would need in the future, that time being now and have gone to upload the .pst file into my new machine, however an error message stating that I dont have permission to access these files to import them. How can this be considering it was me the set up the files?