By Diane Poremsky
Many Outlook 2003 users want to know how to convert the PST (personal store) file they used with older versions of Outlook to the new Unicode format. Unfortunately, you can't convert a PST from Outlook97/2002's ANSI (American National Standards Institute) format to Unicode or from Unicode to ANSI. You'll need to move, copy, or export the contents to a new message store.
By default, Outlook will create a Unicode personal store when possible. The exception is when creating PSTs for use with IMAP (Internet Message Access Protocol) or Hotmail/MSN accounts, as those accounts require ANSI.
Administrators may want to prevent users from adding these accounts types to Outlook by forcing the use of Unicode PSTs only. Other administrators may want to force Outlook 2003 to only create ANSI PSTs to insure backwards compatibility with older versions still in use on the network.
Either is accomplished by setting a registry value for NewPSTFormat. As always, use extreme care when modifying the registry and if you're not sure what you're doing, don't do it!
To force Unicode or ANSI PSTs, navigate to HKEY_CURRENT_USER\Software\Microsoft\Office⏻.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.