Secure Digital High Capacity: An extension of the SD standard, SDHC allows standard compliant capacities in excess of 2 GB.

When you connect a Secure Digital High Capacity (SDHC) card to a Windows Vista Service Pack 1-based computer, the SDHC card is not recognized. However, this issue does not occur when you use the same SDHC card on a computer that is running an original-released version of Windows Vista.