yafray.some help needed

i downloaded yafraysome months ago.everything worked well for some thime.
but today when i trydYafRay_Render:blender.exe- Unable To Locate DLL to render with yafray i got a messatheYafRay_Render:blender.exe- Unable To Locate DLL

?
also do i need
NET Framework 1.1
to use yafray?

https://blenderartists.org/forum/viewtopic.php?t=46659&highlight=net+framework+yafray