Make sure your SATA ports are enabled in BIOS. On your motherboard, connect your SSD to the first SATA port (port 0). If you have any other drives connected (IDE), move them off port 0, or I would disconnect them temporarily until you have sucess seeing your SSD.
Thanks for your replies. I'm usaing ns Asus UL30VT noebook and the BIOS does not allow much control. I satrted by following the Intel upgrade software instructions but the drive (fitted in an external USB) was not recognised. After some research in the foru it seems this is a common problem, and only some USB enclosures will function. I tried three without success.
Migration is difficult because the 160Gb ssd drive is smaller than the original 500Gb, although the C system partition is only 120Gb.
I gave up, but thanks anyway