Hi Verwood21,
the specifications for the VPCL12S1E/S state..
Memory
* Memory Size (MB)4096
* Memory Speed (Mhz)800
* Memory TypeDDR2 - PC2-6400 (SO-DIMM)
* Max. Supported Memory (MB)12288
You can also go to the Crucial.com site and use their Crucial System Scanner tool, use the following link to access the tool:Crucial System Scanner tool
This tool should inform you what's currently installed in your vaio as also recommended an upgrade.
