hi thanks for the info on your cpu i would try and upgrade to 768mb of ram as 512 does seem a little low on a 478 socket mobo, sometimes SIW makes a mistake but not all the time
as for your hard drive question i have never tried to copy twice but i dont see any reason why it would not be ok unless there is data on the 300gb slave that you want to keep because when you do copy a hard drive it completely erases the target drive, also i forgot to mention when you do copy a hard drive it will partition the target hard drive to the size of the drive you where copying leaving the rest unallocated, you will then have to create a new partition with the unallocated space using the same file system and then merge the two partitions