Notebook-drive enclosures are usually powered by their USB or FireWire connections, so no external adapter is necessary. Plug the enclosure into your PC’s USB, FireWire, or eSATA port. Mac and. you. Aug 05, 2013  · The Cause of "Read Only" Disk Errors. I have a USB drive that I purchased and use with various PCs at work and school. I am able to open the drive and can even copy files…