There might be two reasons for this issue. Initially, the battery might be dead. In which case, you must replace it with a new one or charge it up in order to resume using the device. Secondly, the hard drive might be broken. This is a more serious issue and it requires the hard drive to be replaced with a new one. For more information refer to Sony Handycam DCR-SR42 Troubleshooting Guide

Since all of the recorded images/ videos save on the hard drive, there is a strong possibility that it might be full. Try deleting some of the media in order to make more room for new items. It is also possible that the temperature of the device might be too high or too low for it to properly function. In this case, discontinue the use for a while until the temperature reverts to normal. In case of a broken hard drive, please replace it immediately. For further information please refer to Sony Handycam DCR-SR42 Troubleshooting Guide

Ensure that the cable is securely connected to the computer but at the same time that it is not connected through the USB hub as these are not supported by this device. A direct connection from the camera to the computer is required. If problem persists, try uninstalling and re-installing the USB drive. For further help, please refer to Sony Handycam DCR-SR42 Troubleshooting Guide

Hey,

I'm not too sure. Try just pushing it back in.