How can I save files and be able to transfer them to my pc in my Nokia Lumia 510. Files received via Bluetooth cannot be opened in my Nokia Lumia 510. I'm just told file not supported and given a delete option. What can I do?
You could put the file you need in a .zip file and than transfer it to your phone. Windows Phone supports .zip files, you can even view the content of it.
Have you tried transferring files via usb cable and the windows phone app it may offer to convert file before transferring it like it does with audio and video files