Newbie Raid Problems

Hello everyone, this is my first post ever, but I have been a long time browser. Tom has solved many PC problems in the past. Thank you all for that.

Now, I have built my own PCs for about 10 years now, I am 25, and this is the first time I have ever tried using RAID config. My friends really urged me to do so, and another actually told me to RAID my windows drive (that didn't work out so well).
Anyways, about 2 years ago I built this comp which uses Vista and has a 3-drive Western Digital RAID 0 setup. At first I did this for improved gaming performance, but lately I have just been installing to the Crive. (I do want to start using it again but I am concerned over some events that have been happening recently)

Over the past year or so, I have been getting notifications from Intel Matrix something, that "an error has occurred". The fix is to open the program as an admin and simply "set status as normal". I'm not sure how much of a fix this is and it's unnerving.

Recently, I moved a lot of data from the C drive to the RAID drive. Upon attempting to move someting back, I noticed a hang in the system. Not too, too bad, but definitely noticeable. I assumed there was an error, so I restarted. Upon restart I was shown that there was in fact an error right above the "Press Ctrl-I to configure RAID volumes".

I let that pass and Windows said I should do a check, so I let it perform CHKDSK. Apparently, nothing was wrong. No files in bad sectors, no bad sectors, nothing wrong at all.
NOW, the message, instead of saying "an error has occurred", it says "a RAID volume is failing, please backup information immediately" or something like that.

What I would like to know is this:
Is there really a problem with the hardware, or the software?
Is there a way to check disk health while the disk is in a RAID?
I picked RAID 0 because of performance, is there a better solution that provides both performance and stability?
Should I decide to keep a RAID 0, should I keep it to only two drives? The drives are 400GB with 8.5ms... is this illogical for a RAID 0 config? Logically these drives should be storage and I should get two 10,000s for the RAID 0 right?

I found that once I backup the data I can split the RAID and check each individually for errors. When that happens, and I remove the drive that is affected, what should I do with the other two drives? Also, should I just buy another 400GB drive or get a cheap external on tigerdirect? they have a 1TB one for 109$...


THanks
-Jeremiah