Hi Nadya
Yes the key would be +/-16 chars. However, getting the harddisk serial number is a standard API call. Someone else has already given the code in another thread. The key could also be shortened in various ways. I just thought it was quite easy and removes the need to check the table (any table) for duplicates.
In the End, we will remember not the words of our enemies, but the silence of our friends - Martin Luther King, Jr.