Genealogy aside, please buy an external drive anyway. I am speaking from experience. As an IT consultant, friends often come to me when their computers have died or have viruses/malware. The first thing they ask me is if I can save their photos. Most of the time it's not a problem, but when a drive fails, there isn't much I can do that isn't going to cost them a lot of money. Restoration and retrieval of data off of a failed drive costs thousands of dollars. An external harddrive at best buy is under $100. SO please buy a drive and keep a second copy of your picture on it also. I personally have 2 small drives I keep my backups on, but I live in Louisiana and Hurricane aren't very nice to pictures.