On a Mac, you can print your iMessages from Apple's Messages application. Unfortunately, the Messages desktop app does not display SMS, only iMessages. This results in incomplete conversation threads.
On Windows, there is no equivalent to the Messages app. To view or print text messages on a PC, you will need third party software.
iMazing offers two easy solution to print text messages and iMessages on both Mac and PC:
Anyone who wants to easily print their text messages from their computer.
Download and install iMazing on your Mac or PC computer
To print your messages:
☁ iCloud Messages Update: The biggest new feature in iOS 11.4 is the ability to sync all of your text messages and attachments via iCloud. If you enable iCloud Messages, iMazing will still be able to display and extract your messages like before, but some older attachments may be removed by iOS from your device and kept in the cloud. Text content is not affected.
💡 Tips: Use the CTRL/Command, or SHIFT keys to select multiple contacts or messages. Selecting multiple conversations aggregates them in the main view.