Steps to Move the PST
 
First, close Outlook then make sure Outlook is not listed in Task Manager, Processes tab a few minutes after you close it.
Open the profile (Control panel, Mail) and click on Data files.  
Select the IMAP acct and click Open Folder to open the folder containing the PST.  
Move the PST to the desired location. Do not rename the file Outlook creates a new file in the default location if you try to rename it - you can only move it.
Switch to the Data Files window and double click on the account's data file.  
Now you'll get the 'can't find' error and can tell outlook where to find it.  
Close the dialogs and you are ready to restart outlook.

Export the Categories key
 
Quit Outlook.
On the Windows taskbar, click Start  , and then click Run  .
In the Open box, type regedit and then click OK.
In
HKEY_CURRENT_USER\SOFTWARE\Microsoft\Office\9.
0\Outlook\Categories select the MasterList subkey.
On the Registry menu, click Export Registry File.
In the File name box, type a name for the key, such as Categories.reg, and then click Save.
Copy this registry file (Categories.reg) to the desktop of your new computer and double-click it to update the registry and add your custom categories to the Master Categories list.