Well, I left my computer for about an hour with a few applications running, when I returned I was prompted for a boot device. I've had the computer for over a year now and I have never seen this before. After rebooting it took around 10-15 minutes for windows to load, then when it booted up it was very slow/choppy, applications loaded in around the same time I guess, but my cursor was pausing every few seconds and sounds were skipping from any application. I checkd eventviewer and noticed these errors: The device, \Device\Ide\IdePort0, did not respond within the timeout period. The driver detected a controller error on \Device\Ide\IdePort0. An error was detected on device \Device\Harddisk0\D during a paging operation. So far I have ran a chkdsk but nothing has changed, the slowdowns are occuring randomly but usually when I run a new application. Im not entirely sure what to do as I haven't changed anything recently, thanks for any help.