Basically access an website, it may identify if im utilizing a virtual machine ?
More particularly an Vmware image?
And when the web site has the capacity to.. How do i prevent it?
Web servers are only able to tell particulars concerning the browsers through their user agent string. Unless of course you are utilizing a special internet browser (unlikely) that picks up it's running inside a VM, then your web server should not know. Regardless, UA strings are simple to switch to whatever you would like these to be, so that you can always make believe you be something you are not.
Take a look at this useful Wikipedia article.