Below there are the steps in order to run Android Platform in your Computer ( using Virtual Box )
Go to the Live Android Google Code Project and download the latest liveCD (0.3 as of this writing. Torrent available here.)
Make a new virtual machine in VirtualBox. Call it “Android” or some other witty name if you are motivated to do so.
Choose the Base Memory Size. VirtualBox defaults to 256MB. Since the HTC Dream (AKA the T-Mobile G1) has only 192 MB Megs of RAM, I figured that this is probably enough.
VirtualBox asks you to select a virtual hard disk. Since we are running Android from a live CD, we don’t need one. Uncheck the box to choose a virtual disk, and check “Continue” when the warning box comes up.
Finish creating your virtual appliance, then select “Android” (or whatever your machine name is) from the main VirtualBox window, and click the “Settings” button.
Go to the CD/DVD-ROM section and check “Mount CD/DVD Drive”, then select “ISO Image File”. Click the folder icon to the right and select the “liveandroidv0.3.iso” file that you just downloaded. Press ‘OK”.