Do you have a file with PST extension? Want to open the PST file on your Windows 10 PC but don’t have Microsoft Office Outlook installed? Want to open the PST file without the Outlook software? In this guide, we will understand what a PST file is and how to open it without installing Office Outlook on Windows 10. A PST file is nothing but Outlook data file and contains emails, contacts, and calendar events in your mailbox. You can export all emails, contacts and calendar events from Outlook.com or Office Outlook program to a PST file to back up your inbox. What if you have a PST file but don’t have Outlook software installed on your PC? Well, luckily, there are a few free tools around to help you open and read PST file without the Outlook software. IMPORTANT: Please make sure that the PST file is not open with any other program before opening it with one of the below mentioned tools. SysInfoTools PST File Viewer SysInfoTools PST File Viewer (free version) is an excellent piece of software designed to open and read PST file contents without Outlook. The software can even open corrupt and large PST files, according to the developer of the software. The best thing about this software is that it can export all data like your emails, calendars, tasks and contacts to an HTML file. A paid version of the software is also present with additional features, but the free version is sufficient for all users. Download SysInfoTools PST File Viewer PST Viewer PST Viewer is another free software out there to open and read emails, calendars, contacts and other information from PST files without having to install Office Outlook software. The software can easily open large PST files without any issues. This software supports opening multiple PST files, unlike its competitors. PST Viewer can also be used to open password protected PST files (you need to know the password though). And like SysInfoTools PST File Viewer, this tool can also open and read corrupt PST files without any issues. Download PST Viewer Free PST Viewer Free PST Viewer from GainTools is yet another software developed to enable PC users to open and view PST files without the need of Office Outlook software. The Free PST Viewer can open only one PST file at a time. The program is extremely easy-to-use and requires no expertise. Besides opening PST files, it can also convert PST to MBOX, MSG, and EML/EMLX for ten times. The current version of the program is compatible with XP, Vista, Windows 7, Windows 8/8.1 and Windows 10. Note that when you install the Free PST Viewer, it shows that it’s a trial copy. The trail copy works for unlimited number of days. It’s just that you cannot use it convert PST to MBOX or MSG files more than ten times. Download PST Viewer In addition to these methods, you can convert a PST file to MBOX format and then open it with Mozilla Thunderbird, but the catch is that none of the PST to MBOX converter available for Windows are free.