You can upgrade upto 4GB with 0MB non-removable base memory and 2 memory slots

Machine name: Lenovo-IBM IdeaPad B450
CPU options: Intel Pentium Dual Core Processor
Chipset: Intel GL40 Chipset
HD Bus:
Front Side Bus options:
Memory Speed options: PC2-5300 DDR2-667 200pin SDRAM SODIMM
Special notes:-
- Mfgr's System p/n's: 3328-xxx; B450
- Although it is physically possible to install more memory, the system will only recognize 3GB maximum.