Dell forum: BIOS/configuration problem - Dimension 8400

Dimension 8400, Windows XP Media Center edition, raid 0 array, 3 gb RAM.

I have a Dimension 8400 with a raid 0 disk array.

I recently upgraded the memory from 1gb to 3gb (added two 1gb modules), but noticed the system reporting only 2.5gb of RAM. I opened the case and found where one of the 512mb modules was not seated correctly on one side. I reconnected it, but the pc would not boot (just a blank screen with a cursor in one corner). I checked again and found where I had apparently knocked one of the clips loose holding the RAM modules. The computer booted up ok after fixing that problem.

However, now on subsequent boots, I receive the following message on the startup screen:

Drive 4 not found: parallel ATA, PATA-0 (PRI IDE MASTER)

Drive 5 not found: parallel ATA, PATA-1 (PRI IDE SLAVE)

Press <ctrl-I> to enter cinfiguration utility

strike F1 to continue, F2 to run the setup utility

If I press the F1, the computer starts and runs fine.

What changes do I need to make, if any, in the setup utility? I'm not sure what to do about the problem. I'm ok with how to make changes in the utility, but am not sure what I need to change. Is this an indication of a potential drive failure?

Thanks for any help anyone can provide.