Having similar issues windows 7 reconzies that i have 12gb of ram. but only using 4gb my specs are
ASRock 970DE3/U3S3 AM3+ AMD 770
AMD Phenom II X4 965 Black Edition
G.SKILL Ripjaws Series 12GB (3 x 4GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Desktop Memory Model F3-12800CL9T-12GBRL
ASRock 970DE3/U3S3 AM3+ AMD 770
AMD Phenom II X4 965 Black Edition
G.SKILL Ripjaws Series 12GB (3 x 4GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Desktop Memory Model F3-12800CL9T-12GBRL