RAID 0 Problem

Hi all

I may have done a big mistake and I want to know if it can be "undone"

Some weeks ago, my friend came to help me creating a RAID 0 (Stripping) on my PC
The problem was, when we created the RAID, my 3 HDD were connected (2 x 500Go (for the RAID) and 1 x 1000Go (for data))
The GIGABYTE utility told me that the RAID was done and it was 931.5Go big (which is supposed to be good because 2 x 500 = about 931.5). When it came to installation, there were 2 x 931.5Go unallocated space (1 for 2x500 and the other 1x1000)
But wasen't it supposed to tell me that the 2nd 931.5 was already allocated ?? Anyway, I did nothing (not even format !) and closed it all. Then I got that 1To out of the PC to start the RAID again. I needed to create a new one (that was when I started to panic !!) so I did. Formated and installed Win7. Put the 1To back but when I booted, I saw the following (or something like it):
ST3500320AS -- 465Go -- Disk Member 0
ST3500320AS -- 465Go -- Disk Member 0
ST31000528AS -- 931.5Go -- Offline Member

I wonder if I can recover back any useful information that were stored on that disk.

Does anyone have information I could use or should I just format and forget all about recovering ??

Thanks in advance