Many users think they’re doing something wrong or that their handheld is malfunctioning when an SDHC card fails to work with their Windows Mobile device. Fear not, dear friend; you are not the problem, nor is there anything wrong with your PDA or smartphone. SDHC cards are not compatible with any Windows Mobile devices currently sold in the United States, and, in fact, are compatible with relatively few non-Windows Mobile devices on the market as a whole.