RAID Problem - Can't Boot Up

I had my Hard drive in RAID few weeks before when my friend played around my computer and just did it. But now i wanna it back to normal which should have 640GB HDD instead for 320GB HDD.

Here is what I did, went into Intel Matrix Storage Manager and did "Reset Disks to Non-RAID" thinking it would work but turns out it didn't, i don't want to lose any data.

Here is what is showing up
RAID Volumes:
ID name Level Strip Size Size Status Bootable
0 ..... RAID0(Stripe) 128kKB 596.2GB FAILED NO

Physical Disks"
Port Drive Model Serial # Size Type/Status(Vol ID)
0 ..... ..... 298.1GB Member Disk(0)
1 ..... ........ 298.1GB Non-RAID Disks

I am not sure I am reading your post correctly, but it appears that you have a RAID array and you set it as a non-RAID array. That will render the drives unreadable as the data is spread across all drives (presuming it is a RAID 0 array as indicated.)

You will need to reset the RAID array and copy the data to another drive or media and then start over.

There is NO way to recover data from a striped RAID array if you break the array.
All the data on the array is split, literally byte for byte, across both drives.
You must re-establish the array. Set the array back for RAID 0, or striped, and see if the controller will/can re-establish the current array. If you haven't messed with the drives too much, the array should start working again.