Which version of windows, and how big / how many of the drives?
Windows XP 32 can only use volumes up to 2GB, so if you're setting up an array bigger than that, Windows won't see it. You need XP64 or Vista64 (Vista 32 *might* work)
The drives might not actually be faulty - use the manufacturers diagnostic tool (they all have them) first. Taking out the 2 drives might just have taken the total size under 2GB, so it now works (when it wasn't faulty in the first place).
The temporary solution is to set up 2 arrays across the drives - as long as both are under 2GB you're set and can use them in windows.
I had the same issue, but 2 volumes is a pain, and if the intel matrix manager detects it need to rebuild, it takes forever as it does both at the same time (so 8 or 9 days continuous to rebuild vs 24 hours for one huge one).
I'd strongly advise taking the hit and going for a 64bit OS if you want a huge single volume.
I'm now battling an annoying problem - i've got a 'lazy' drive that is slow to wake up and so triggers the rebuild a lot - i'm going to swap it out. This is why the drive makers sell the RAID editions (RE2 on WD or ES from Seagate etc) that are designed to let the RAID controller fix the errors instead of the drive. I'm just too mean to pay the extra £20 a drive to buy them though ...