I have a toshiba l675d-s7101 it comes with two 2gb sticks of ram. It can be upgraded up to 8gb of ram so I recently bought a 4gb stick of crucial ram so I would have 6gb. The 2gb stick is samsung brand the 4gb is crucial. When I plugged the 4gb in my computer only recognizes the 2gb. It says my computer takes ddr3 pc3-106000 which is what both sticks are. Am I doing something wrong installing ?
You cannot install different ram cards together. You need to have the exact same ram cards if you are placing multiple cards. Also cards of different memory sizes are not recommended. You can try out different combination of cards to make them work but I'll advice you to install the 4gB and remove the 2gB stick.
For best results put the cards in 2nd and 4th slot.