I have reviewed many of the "Write Protected" questions and have tried to do some of the results given, but it just has not happened.

I bought 2 jump drives on eBay, it is a Hitaichi HTS543216L9A300. My wife transferred a lot of her files onto this drive last night, and this morning, when she plugged it back into the computer, it says that it is write protected and we can not add any more info onto the drive.

How can we remove this protection

I have seen this happen when the drive is being accessed by the PC and gets stuck in a loop for some reason.

First I would try the simple reboot if you have not done that yet

If that doesn't work... turn off PC. Unplug hard drive from computer... turn on PC... after done booting up... plug the drive back in (assuming this is a usb drive)

Check to see if there are any software, driver, or firmware updates from the manufacturers website.