When moving from Mac Outlook to Windows Outlook, converting OLM files into PST format becomes necessary because PST is the supported file format for Microsoft Outlook on Windows.

With PDS OLM Converter Tool
, users can quickly migrate mailbox data from Mac to Windows while preserving:

Emails and attachments
Contacts and address books
Calendars and appointments
Tasks and notes
Folder hierarchy and metadata

After conversion, the PST file can be imported directly into Microsoft Outlook on Windows systems.

https://www.perfectdatasolutions.com/en/olm/olm-to-pst-converter.html