You will not be able to repair the corrupted PST. I would restore the original mailbox from a backup and then break the pst down into several smaller pst’s keeping them under the 2GB range. For this you can use scripts that can easily be found on the internet. One such site is <a href=”http://gsexdev.blogspot.com/2007/01/exporting-mailbox-larger-then-2-gb-and.html”>http://gsexdev.blogspot.com/2007/01/exporting-mailbox-larger-then-2-gb-and.html</a>
Another option is to re-activate the mailbox after you have restored it from backup. Then open it with Outlook 2003 or 2007 and archive it using the Outlook client instead. <a href=”http://support.microsoft.com/kb/830336″>Outlook 2003 and 2007 use unicode format</a> which does not have the 2GB limit.