xp home hard disk constant access slow performance

Hi,

After starting up my laptop from hibernation one day, the CPU was running non-stop on “explorer.exe”, so I did a hard shut down (hold the power button down for 5 seconds). When I booted the computer back up, the hard disk was constantly accessed – I can see the light blinking non-stop, and everything runs very slowly. It takes minutes to execute a command. This happens everytime now, and I have to use Knoppix to use my computer. Can anyone offer help?

Thanks,

Robert