I bought an external hard disk (FreeAgent 160GB, Model # ST901603FGE1E1-RK) in February 2008. The purpose is data backups of my PCs (all XP-SP2). Whenever I use this external hard disk (from any of my PCs), there are always a few occurences of the following in Event viewer :- Type: Warning Source: Disk EventID: 51 An error was detected on device \Device\Harddisk2\D during a paging operation My other external hard disk is a Western Digital (procured about a year ago), and so far, I have not come across any such error message when I use it. Should I be concerned about this error event in my Seagate FreeAgent? Since this is a data backup device, I am worried.