Thanks, I can build it now with some warnings,
But I'm not sure how to run it, I copied it to C:\Program Files\Mozilla Firefox\plugins (which did not exist), and also to "C:\Program Files (x86)\Mozilla Firefox\Plugins" which already existed, and opened test.html in FF Chrome and IE8, but I only got the buttons, and some empty space above it.
By the way here are the build warnings if you are interested
1> juce_browser_plugin_wrapper.cpp
1>C:\Program Files (x86)\MSBuild\Microsoft.Cpp\v4.0\Microsoft.CppBuild.targets(990,5): warning MSB8012: TargetPath(D:\myname\juce\JUCE\extras\browser plugin demo\build\win32\Release\JuceBrowserPluginDemo.dll) does not match the Linker's OutputFile property value (D:\myname\juce\JUCE\extras\browser plugin demo\build\win32\Release\npJuceBrowserPluginDemo.dll). This may cause your project to build incorrectly. To correct this, please make sure that $(OutDir), $(TargetName) and $(TargetExt) property values match the value specified in %(Link.OutputFile).
1>C:\Program Files (x86)\MSBuild\Microsoft.Cpp\v4.0\Microsoft.CppBuild.targets(992,5): warning MSB8012: TargetName(JuceBrowserPluginDemo) does not match the Linker's OutputFile property value (npJuceBrowserPluginDemo). This may cause your project to build incorrectly. To correct this, please make sure that $(OutDir), $(TargetName) and $(TargetExt) property values match the value specified in %(Link.OutputFile).
1>juce_browser_plugin_wrapper.obj : warning LNK4104: export of symbol 'DllGetClassObject' should be PRIVATE
1>juce_browser_plugin_wrapper.obj : warning LNK4104: export of symbol 'DllCanUnloadNow' should be PRIVATE
1>juce_browser_plugin_wrapper.obj : warning LNK4104: export of symbol 'DllRegisterServer' should be PRIVATE
1>juce_browser_plugin_wrapper.obj : warning LNK4104: export of symbol 'DllUnregisterServer' should be PRIVATE