How do I save my chat history for Nokia s60?

Saving your messages

Your WhatsApp messages are automatically backed up and saved daily on your phone's memory. If you uninstall WhatsApp from your phone but don't want to lose any of your messages, be sure to manually back up your chats before uninstalling:

Open WhatsApp and go to Options > Settings > Chat History > Backup chat history.
Tap Yes to back up chat history.

Restoring your messages

If you are deleting and reinstalling WhatsApp, you will be prompted with a message to import your backup after you first open your new copy of WhatsApp. Tap Restore and your chat history should load.

If you need to transfer your chats from one S60 phone to another S60 phone, transfer your SD card to your new phone before installing WhatsApp on it. If you do not have an SD card, you will need to copy the entire ‘wa’ folder from your old phone into your new phone’s memory. Install WhatsApp and click on Restore when you see it, and your chat history should begin loading.

Here is some technical information about your backup

Backup files are saved in the ‘wa’ folder and are called MsgStore.bak.
Backup files are saved to both your phone’s internal memory and SD card, but only given that there’s enough space.
Backup files are only valid for 7 days after last saved. Make sure you import your chat history before it expires!
Backup files are phone number sensitive; they will only work with the same phone number.
Backup files are saved in a format to be opened with WhatsApp. If you want to read your conversations on your computer, you can send them as .txt file from WhatsApp to your email. To learn how to export your chat history, read this article.

Cheers,
WhatsApp Support Team