I am running Windows Server 2003, and the server is very slow, with slow disk I/O and extremely high CPU use. What can I do?

This may be because your server has started using PIO transfer for disk, not DMA, which we have seen happen to Windows 2003 servers. To change this back you will need to uninstall the IDE driver and reboot the server. In Device Manager, uninstall the IDE channel from the IDE controller, then restart.