You can't change it later (99% of laptops.)
You can always get more RAM but today 1G is just dandy.
nd to chose between the 2:
1.upgrade the CPU from Core 2 Duo T5600 to Core 2 Duo T7200
2.double the memory from 1GB to 2 GB
nomal office use and slighly gaming.
which option is better for overall performance?