Firefox PE Seperate History

I would like to see a feature that separates the Firefox history based on which computer you're using. This could be done using the Windows product key or a user-host name combination. When I use Firefox PE at work I only want to see my history from work. Sometimes my history has things that are NSFW because I use it in several places. I find it unlikely there is an extension that does this, since Firefox is typically non-portable.