i recently bought a macbook off of craigslist and upgraded the RAM to what i thought would be an OK 4gigs.

After tooling around the internet and passing by Crucials website they state my macbook can only handle 2gigs.

here's my specs;

Model Name: MacBook
Model Identifier: MacBook2,1
Processor Name: Intel Core 2 Duo
Processor Speed: 2.16 GHz
Number Of Processors: 1
Total Number Of Cores: 2
L2 Cache: 4 MB
Memory: 4 GB
Bus Speed: 667 MHz
Boot ROM Version: MB21.00A5.B07
SMC Version: 1.17f0
Serial Number: W8718V72YA3
Sudden Motion Sensor:
State: Enabled

the macbook see's all 4gig but my question is;

Is it able to use all 4gig?

any solid input would be great.