Vista will have an inbuilt undelete system based on the Windows 2003 "volume shadow copy" technology, Microsoft has revealed. The system, called "Previous Versions" under Vista allows end-users to retrieve older versions of files as well as deleted versions. As APC Magazine points out, the feature, which will be enabled by default in Vista, is great for Joe Cubicleworker who has just overwritten his boss's PowerPoint presentation by mistake. But it may be very bad news indeed for anyone who discreetly deletes a document and assumes it is gone. Of course, undelete has always been possible unless a file has actually been overwritten with other data, but under Vista's versioning file system, that will certainly not happen, meaning your 50:50 chance of a file being recovered by your tyrannical boss is now a 0:100 chance.