Create another PST file and move some of your older email into that PST file.
For example I break down all my email by year so that my PST files don’t get to large.
Looks like you have an ANSI pst which is set at 2gb default size. You cannot increase this size.
The solutionis to create a new pst file but in unicode format and then move some of the contents from the old pst file to the new pst file. You dont have to move all contents, ~500mb should be sufficient.
Once you have done that you should compact the old pst file.
UNICODE supports pst files of size 20gb.
I have had success using Ontracks Data Recovery suite to deal with this problem. On another PC with Outlook 2003 and the Data Recovery softwre, you can ‘repair’ the .pst file to larger than 2GB. Then, use Outlook to Export older data to another .PST file.
Also, this little tidbit may be helpful:
To force Unicode or ANSI psts, navigate to HKEY_CURRENT_USER\Software\Microsoft\Office\11.0\Outlook
Add the NewPSTFormat value with one of the following values:
Prefer Unicode PST: 0 (default)
Prefer ANSI PST: 1
Enforce Unicode PST: 2
Enforce ANSI PST: 3
By using a value of 2 or 3, you can restrict all new .pst files to either the old format or the new format. Note however, that Outlook will not open the mailbox folders if you are using IMAP or Hotmail/MSN accounts and try to force Unicode format pst’s – they require the ANSI format used by Outlook97/2002.