If some or all of the memory is not recognized during the boot-time memory check or in CMOS Setup, power down the system, rearrange the modules, and restart the system. If no documentation is available, experiment by moving modules around. Best practice is to check the manual before installing memory. Some motherboards don't care which module you install in which bank. A few motherboards require smaller modules to be installed in the lower banks. For example, if you are installing two 256 MB DIMMs in a dual-channel motherboard that has four DIMM sockets, with 128 MB DIMMs already installed in the 0 slots for channel A and channel B, you may have to move those 128 MB DIMMs to the 1 slots for channel A and channel B and install the new 256 MB DIMMs in the 0 slots for both channels. Some motherboards require higher-capacity modules to be installed in lower-numbered slots.

For example, if the motherboard has two slots each for channel A and channel B, numbered 0 and 1, fill the slots for channel A slot 0 and channel B slot 0 first. If you are installing memory in a dual-channel memory motherboard, install memory modules in pairs, filling the lowest numbered slots first. Fill slot 0 (or 1) first, then the other slots sequentially as you add modules. For example, if a single-channel memory motherboard has four memory slots, they will be numbered 0 to 3 (or 1 to 4). Most recent motherboards automatically detect installed memory modules regardless of the slot they occupy, but it is good practice to install modules in the lowest numbered slots first. Installing memory modules is straightforward.

Blue or white slot for ram first