You can download a Virtual PC VHD (Virtual Hard Drive) file containg Windows Vista and Office 2007, including Access 2007, from Microsoft Office 2007 Professional VHD. A link to download the now free Microsoft Virtual PC is also on that same page.
Note that you will need at least 512 spare MB of RAM not currently being used and 10 Gb of hard drive space.. That file is somewhere between "448.8 MB - 2548.8 MB*" according to that page. I'd think that you'd be safe in assuming the 2.5 Gb download size.
You also have to sigh at the following sentence. "This download offers you the benefits of registering with Microsoft." Benefits, uh huh. Marketing speak. Ah well, it's been my experience that Microsoft is relatively benign when it comes to sending you unwanted emails.
Ahh, now, Microsoft folks were quite smart on this large download. They split the download into four parts. I won't be downloading it though.
Added: I won't be downloading the VHD because I already have Office 2007 including Access 2007 installed on my system. Thus no need to download the file.