Older versions of Microsoft Outlook save PST files in ANSI format, while newer version creates these files in Unicode format. While ANSI files can be opened in newer versions of Microsoft Outlook many people find it more convenient to covert these files to Unicode when they upgrade their Outlook program.
Depending on the version of Outlook that you are using, your PST file will come in one of two formats.
If you are using a version of Outlook that is 2002 or older, the PST files created are formatted in American National Standards Institute (ANSI) format. ANSI format PST files are the only PST files that these older versions of Outlook can read.
Starting with Microsoft Outlook 2003 and later, the default format for PST files is Unicode. Microsoft Outlook 2003, 2007, 2010, and 2013 can also support the ANSI format, however, so it should be possible to open a PST file created in older versions of Outlook in these newer version.
How to check my PST file format?
- Open “Data File Management”
- In Outlook 2003 or 2007: Go to “File” then look for the option that says ”Data File Management”.
- In 2010 or 2013: Go to “File” then “Info” then “Account Settings”. In account settings, look for the tab that says “Data Files”
- Find the PST file you want to check. Double click.
- You should see one of the following in the “Format” field.
- “Personal Folders File” – Unicode format
- “Outlook Data File” – Unicode Format
- “Personal Folders File (97-2002)” – ANSI Format
- “Outlook Data File (97-2002)” – ANSI Format
Why change the format of your PST file?
One of the main reasons to change your PST file from the ANSI format to the Unicode format is to get around the size restrictions.
A PST file in the Outlook 97-2002 format has a size limitation of 2GB. If your PST file is approaching 2GB or has gone over that limit, then it could slow Outlook’s operation. It could also result in data loss as a PST file that is oversize can get corrupted.
If you convert your ANSI PST file to Unicode, you increase the file size limit to 20GB and more. With Outlook 2010, 2013, and 2016, the file size limit is 50GB.
How to change the format of your PST file
If you want to convert a PST file created in Outlook 97-2002 from ANSI to Unicode, an easy and convenient way to do so is with DataNumen Outlook Repair.
- Close your Outlook program then open DataNumen Outlook Repair
- Find the PST file that you want to covert and select it.
- Make sure that the combo box is set to Outlook ”97-2002”
- Choose a name for the new file that will be created during the conversion process. The new file will be named “filename”_fixed.pst
- Select the format you want the file to be converted to. As we want to file to be converted into Unicode, make sure the combo box is set to “Outlook 2003-2010”
- Click on “Start Repair”
You can also convert a Unicode file to ANSI this way, just change the values you set in the combo boxes. So the first should be “Outlook 2003-2010” and the second “Outlook 97-2002”