My Windows directory is about 7,8Gb at the moment so 8Gb as primary drive would be too small. But what you probably can do is using vlite and remove for example the media center and other stuff you do not need to test/ run the normal things of Windows 7. My complete C:\ , installation of Windows 7, office, opera, avg, gimp, ccleaner, wsftp, foxit, java, orov and infrarecorder is 8,8Gb at the moment with an one user setup.