That sounds like a checkdisk trying to run, which is either a sign of corruption on the drive or possible failure. The fact that it reboots a second after it either means it can't read from the drive properly (I/O error) or your motherboard is having power fluctuations.
One way to check if it's the drive at fault is to get a LiveCD with comprehensive disk checking tools. If your case is like the one I dealt with a couple months ago (overheating caused a SeaGate HDD to fail), it will basically tell you that the drive fails within 10 seconds of trying to read the data from it (PCB failure within the HDD, not mechanical). I don't have the tools on hand, so I can't suggest anything, but the more skilled users on the forums (like FAST) would probably know.
If you have no idea what I just said, the easiest fix is to take it to a service shop and ask them to test the drive.