Solved System Properties Shows Wrong Installed Memory (RAM)

I have recently installed 3 new 2 GB DDR2 rams with 1 previously installed 1 GB DDR2 ram. The system bios menu shows 7 GB. see image below
https://ibb.co/nf7oF7
But Windows 8.1 shows 4 GB, while CPU Z shows 7 GB too. see images below.
https://ibb.co/isBthn https://ibb.co/hJPca7 https://ibb.co/jwPh8S https://ibb.co/dTYs8S https://ibb.co/hUpX8S https://ibb.co/iXZ4Nn
Kindly help me regarding this issue.