I assume you are using a web browser to view these images on the other machines (but not coded within a web-page)?
So that you can get an "unbiased representation" of how they will look. Because if you are using an Image Editor (to view them) they may differ more between the different machines. Thus you can get more variation depending program on settings. It could be colour settings, etc.
A web browser has no concept of dpi thus it will appear different to say Photoshop (where you can see print and actual size, etc.) As far as the browser is likely to be concerned anything over 72 dpi is meaningless anyway (or for that matter so is 72 but that's another story).
So what I am saying; since you want them to be displayed in a web browser you should be only using a browser on each PC to compare the final results. Obviously you will be using copies not the master files themselves.