Single SATA drive in a RAID controller

I looked around but i wasnt able to find the answer to my question.

I am fixing my friends computer and am a little stumped. He has problems where it restarts and sometimes it gets errors and it does a CHKDSK when it boots up.

He is running a 2.0 GHz AMD with 512MB of ram on a XP Pro.

My question is because he already has a DVD RW 3 hard drives and some 64MB vid card he went ahead and plugged a Single 320GB SATA drive into one of the RAID Controllers ports. Are raid controllers able to function that way or is it STRICTLY for raid?

I am thinking that his problems might be caused by that or the fact that he runs 4 Hard drives, vid card, dvdrom and a fan off a old 320Watts ATX power supply.

Let me know what you guys think it be much appreciated.

Thanks in advance.

You say he "plugged a Single 320GB SATA drive into one of the RAID Controllers ports". Lots of mobo's these days have SATA ports that CAN operate RAID arrays, but that does not mean thay ARE doing that. In the BIOS setup screens you specify how the SATA drive on a particular port is being used. One option usually is to just use it as a plain drive. Sometimes the BIOS will even make it appear to the OS as just another IDE drive. On those systems, you have to specifically set that SATA port and HDD to be part of a RAID array if you want that feature. So maybe it is NOT a RAID disk.

I'll agree with sturm. Good chance the PSU is too small with all the added components.