When it comes to wiping hard drives, many companies still haven't learned their lesson yet, according to a new study.

Scotland's University of Glamorgan last week released the results of its annual study on hard drive erasure, and the results weren't encouraging.

Each year, university researchers buy hard drives on eBay, at computer shows, or from recycling operations, and then study them to see what data can be found using off-the-shelf tools. This year, the study found sensitive data on 62 percent of 133 working drives purchased in the U.K., which was only a slight improvement over last year's results. (See Second-Hand Drives Yield First-Class Data.)

In one case this year, the researchers found a hard drive containing data belonging to Dudley Group of Hospitals NHS Trust -- a U.K. hospital group -- for sale on eBay. Two hard drives from Marathon Oil also cropped up in the study. Both Dudley Group and Marathon say they have no idea how their hard drives ended up on the secondary market.

As in past years, the university researchers used the study to caution enterprises and end users to fully wipe their old hard drives before recycling or donating them. Simply erasing files is not sufficient, they warn -- data should be fully overwritten and/or wiped using an effective erasure program, they said.

Tim Wilson, Site Editor, Dark Reading