Naturally you can.
The question here is how well it will run.
My personal opinion ( based on my Win7 usage ) is that you need at least little bit more ram if you want to enjoy Win 7 to its fullest.
I have 4 gigs and my ram usage with medioum load on the pc is usually around 1-8-2.2 which is quite close to the limit of yours.
By medium usagei mean:
Microtorrent, MS Office 2007, Skype, msn, Firefox ( 5-9 windows, some youtube, which i noticed tend to eat some ram), MPC ( media player classic running some .mkv movie) and some other misc. stuff.
So i am not saying it won't run properly just that it might at some point start to feel slow and run out of memory it depends on what you do with it.
If someone can provide some info on the CPU ( unrotuantely i am not that informed about Intel Centrino series performance ) .