crains :
i know you probably don't want to hear this... but i believe upgrading to win7 pro would solve your issues...
Upgrading the OS rarely solves an existing problem (though a fresh installation of Win7 might result in other improvements.)
I have run RAID-1 on three different machines. Every time it was supported by BIOS and chipset. None of them were problematic.
I do not advise using any kind of Software RAID or operating system construct; if you lose the OS, you lose the data as well. A drive failure on a hardware RAID-1 leaves you with a single-drive that still runs well.
Just my $0.013 after taxes.