To remove write protection on a Sony Walkman NWZ-S544, first, ensure the device is not locked by checking the hold switch on the side; it should be in the "off" position. If the issue persists, connect the Walkman to a computer, navigate to the device in File Explorer, and try to remove any write protection settings in the properties. Additionally, ensure that the device's internal memory is not full, as this can sometimes cause similar problems. If these steps do not resolve the issue, consider resetting the device to factory settings.
a really long time
Well it depends on what model you have I have a walkman nwz e340 model and it only take about 30 min. to charge but the battery lasts soooooo long. So if you don't have this model, I totally recommend it.