Windy, it is conceivable that the memory cards are incompatible.
I tried a Kingston upgrade to an Advent laptop. Kingston kindly refunded and admitted a probable incompatibility. Contacted Advent, paid bucks more, memory worked.
Next laptop contacted Crucial, their website directed me to the proper RAM. Bought it, fitted and it didn't work. Went to their website, followed the FAQ. Worked a treat. All without any human contact at all. Great service.
Try the Kingston FAQ or Help Line.