Got this reply from Kingston below. H55 chipper cannot handle 4gb dimms:
Please note that although the GA-H55-UD3H is not currently in our list of supported systems, we used to support this model with our memory previously.
Support for this system was discontinued in 2013.
The reason for the discontinuation was the transition to a new type of memory technology.
It appears as though the system, which was released in 2010, is unable to support this newer technology.
The memory used by the GA-H55-UD3H has a 2Gbit chip density - the current chip density is 4Gbit and the Intel H55 Chipset is not capable of using this technology.
Due to the lack of components to build compatible memory modules, the latest revisions of the KHX1600C9D3K2/8GX has been build based on a 4Gbit chip density.
Therefore we were no longer able to support this system as all current memory modules had been updated to the new type.
Unfortunately, we are no longer able to provide you with a compatible upgrade solution, therefore we recommend that you return the product to your supplier.
Should you encounter any difficulties in returning the part to your supplier, please do not hesitate to contact us so that we can look into the possibility of providing an alternative solution.
We apologise for any inconvenience this may cause.