How to enable "Chat History Save" function by edit registry？

@Frank Xiong

If the checkbox Save IM conversations in my email Conversation History folder is greyed out, perform the following steps:

• Open regedit: to do so, click the Start button and then in the Start Menu, either in the Run box or in the Search box, type regedit and press Enter.
• Create the registry backup. Note: you can skip this step, however, we highly recommend to back up the registry before you proceed to modifying its entries.
• Navigate to HKEY_CURRENT_USER\SOFTWARE\Policies\Microsoft\Office\x.0\Lync (x.0 corresponds to the Office version: 16.0 = Office 2016, 15.0 = Office 2013, 14.0 = Office 2010)
• Remove a DWORD entry named IMAutoArchivingPolicy. Note: If IMAutoArchivingPolicy has value of 0 the box will be unchecked and greyed out. If IMAutoArchivingPolicy has value of 1, the box will be checked and greyed out.
• Reboot your machine. After a reboot you should be able to check the box Save IM conversations in my email Conversation History folder.

If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".

Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.