This is a Intel Core 2 Duo processor with a W7 Home OS. I'm trying to upgrade memory to 8 GB from 4 GB. All memory cards are DDR2 2GB cards from Crucial. All are identical and all are newly purchased. The system starts and runs OK on 4GB. These are inserted in to the two blue DIMM slots. Upon inserting either one or two of the other 2 GB memory cards, the system does not get beyond the Windows starting screen. I have to do a forced shutdown to stop the process. Can someone suggest a test that I might run to check the motherboards ability to handle 4 memory cards? Thank you.