Hello Trudy
First scan your photos at around 300dpi,you will find this in your scanner settings.If they were sent to you via email this won't apply.Next make sure they are under 500Kb. as this is the max. on here,check this by right clicking the image >properties.If over 500Kb. you will need to physically resize them.Finally give them a unique name as all filenames are stored & you can't have 2 the same,todays date + initials or something like should do it.
jim