Latitude D630 - upgrading Hard Drive

Hello

I have the Latitude D630. my HD is fine, i just want to replace it with a new and BIGGER one

based on my service tag, the dell support center (over the phone) told me that my pc cn handle as much as 160GB of hard drive. is that correct? i'm interesting in buying the WD Scorpio Blue 500GB but according to what i've been told - it won't work.

would like to her your opinion

thanks