Hi, My computer started crashing recently in various, seemingly unrelated conditions. To preface, my setup is: HP Pavillion dv5250 notebook Windows XP Professional SP2 120GB, 5400RPM Harddrive (SATA, I believe) Symptoms of the crash are the following: System becomes slow (at first) and then unresponsive. The light that symbolizes a harddisk access operation keeps lighting up for a few seconds (2-3 sec each time) and then going off for about 1 second before lighting up again. It continues with this pattern until I reboot the computer by holding the power button. After I restart it and check the Event Viewer, I see multiple entries of a warning under the System heading, several seconds apart, leading up to the time of the reboot. The events always list "disk" as the Source and contain the following: Event ID: 51 Description: "An error was detected on device \Device\Harddisk0\D during a paging operation." (As every event logged, it also provides the raw data dump (in bytes and words). Please let me know if this is important and I will post it. Though, from what little I could find regarding Event 51 warnings, the data is fairly typical and doesn't provide too much information beyond the description). The crash is encountered in various conditions: I first encountered the problem when connecting a new mp3 player I'd purchased through a USB port. I find it odd that the system starts paging the hard drive repeatedly, when I am connecting an external memory device... Then the problem occurred in other circumstances: - when trying to view the properties of the hard disk through the Device Manager - at the end of a game installation - when trying to access the properties of a wireless network card through Device Manager To me, the above conditions seem entirely unrelated. The only possible explanation I can come up with is that there is a problem in communication between the hard drive and external devices through the motherboard or something. I really don't know. If anyone has any insight to offer regarding this problem I would be very grateful, as this has been bugging me for a while now. Also, if there is any other information I can post to shed light on the issue, please let me know.