File access is denied. You do not have the permission required to access the file .pst

Had the above error when trying to add a PST data file to Outlook. Brand new machine, joined to the domain. I had copied the file across the network to the new machine. I tried moving the file into different locations, I tried taking ownership of the file, I tried setting the domain user as a local administrator, check that the ‘Read Only’ flag was not set, I tried moving, instead of copying the file (this has bitten me in the past, believe it or not) etc. After some searching, Google came up with the answer:

icacls file /setintegritylevel L

I found this here:

http://www.office-outlook.com/outlook-forum/index.php/m/400393/

I ran the icacls command from a command window, however I needed to open that command windows as an administrator, otherwise I got a similar ‘Access Denied’ message. One thing I did not check, which probably should be the first thing to check, was running Outlook as an administrator. However, as I usually add PST’s from the Mail option in control panel, this did not immediately occur to me.