RAID 0 is baaad. (IMHO at least). It may seem to improve performance, but the risk you run when one drive fails is tremendous. The thing is the data is split at the block level, and you need both drives to get all your data. Think of a (contiguous) file as a row on a chess board - all the portions corresponding to black squares are on one drive, and the portions corresponding to white squares are on the other - you won't get your data unless both are running. Of course if you're not storing any important data on there (maybe it's just a boot drive with the OS only - no data), then you're free to use RAID 0.
If you want to just copy everything (OS and data) from one drive to another, try XXClone (freeware).
http://www.xxclone.com/
You can find the manual's here
http://www.xxclone.com/ixcman20.htm and there's a guide here
http://www.techsupportforum.com/cont...ticles/47.html
After the operation completes, when you boot from your new drive, everything will be identical to the way it was on the old drive.