Hamburg  - Reliability varies widely among the different software programmes computer users can employ to wipe a hard drive's data trail, according to a comparison of various programmes.

Only one of the programmes designed to delete temporary files or bits of programming left on a hard drive received a ranking of good from the German magazine Computer Bild. Two others were ranked satisfactory. Others garnered rankings of acceptable or problematic.

The three top performers - TraXEx 3.2.3 by Almisoft; Piriform's free Ccleaner 2.19 and Abelsoft's WashAndGo 2009 - were ranked good, or at least decent. Hard drives scoured by lower performing programmes were anything but properly scrubbed, the magazine reported.

Three of the other tested products, priced at between 41.50 and 48.50 dollars, were judged to be too expensive. (dpa)