If you want to open OLM files on a Windows PC, you first need to convert them into a format that Windows Outlook supports — like PST. The best and easiest way to do this is by using the ToolsBaer for OLM to PST Conversion application. This tool allows you to convert your complete mailbox, including emails, contacts, and calendars. This application you can operate easily without any issues. Using the tool does not require any other installation. The software works smoothly on all Windows versions.