BREAKING NEWS: for some reason is stopped working again. I leave the article here in the hope you'll be more lucky than me.
You have just installed VMware Server 2.0 and you are now staring at a web UI (also called "VMware Infrastructure Web Access") message saying "VMware Remote Console Plug-in is not installed or could not be found".
You know it's installed, because you installed it just a couple of minutes before. You can see it in the list of installed applications, you can also see it in your browser's list of installed add-ons. If you try to install it the installation wizard asks you whether you want to remove it, as it also know it's already installed.
Where this problems come from? I really don't know.
However...
Are you using an operating system with a nice feature called UAC (User Account Control)? UAC is that funny idea you ran into the first time you used Vista or Windows 7.
I suggest that you sould:
(here and there you can be asked to restart the browser or the operating system, do it)
I solved the problem this way, I hope it works for you also.