How to backup contacts, calendar and tasks from Nokia Lumia 510

We used PhoneCopy.com service for this guideline. Using it, your can backup your contacts from your Nokia Lumia 510 easily. The whole backup, including the settings, can be done in several minutes.
Download the PhoneCopy application from windowsphone.com. If you do not have a PhoneCopy account yet, press "Register new account" and create it by filling in "Registration" and then press "Sign up".
If you already have a PhoneCopy account, fill in your username and password. To export your contacts, press "Export to PhoneCopy.com". If you want to upload your merged contacts back to the same Windows Phone 7, it is necessary to delete all contacts there first.
With your contacts safely backed up, you can rest easy knowing your data is secure. Log into your PhoneCopy account at any time to view, edit, or restore your contacts.
Some additional tips:
If the sync does not complete, make sure your phone has a stable internet connection and that background data is enabled for the PhoneCopy app. A brief pause and retry usually resolves the issue.