I have a Pentium III system with 128MB of RAM and a 20GB IDE hard disk running Windows 98; I run a database on this system. I need to add another 20GB IDE hard disk and set up the two disks to duplicate each other whenever any changes occur to the database. (My goal is to add redundancy to protect client data in case one of the disks fails.) I want to install Windows 2000 Advanced Server and configure the system to dual boot so that I can use Win2K AS's software mirroring. Do you recommend this approach? If not, can you suggest a better option?

Win2K uses dynamic disks for software RAID. Win98 can't read these dynamic disks, so your plan won't work. Instead, I suggest that you buy an inexpensive IDE RAID controller (e.g., Promise Technology's FastTrak66 Ultra ATA EIDE RAID controller card, which costs about $60). You can then easily create a mirrored set of Win98 disks without installing Win2K AS.