Back when using W2K, I switched to DK from Norton. All through the various incarnations of XP, up to now XPcorp, DK is still my favorite. Very fast in general & you're not locked into useless unnecessary settings, like with Norton. The Paging file & MFT frag guard can be configured at will & used when you want. Depending on your system setup, you need control over this function, for optimum performance. By the way, I only use NTFS partitioned Disks.