Download and Install CPU-Z from the link given below. After installing, go to the ram section and select the slot in which u've installed in. If ur not sure in which slot, then do the trial and error method.
http://dw.cbsi.com/redir?edId=3&siteId=4&oId=3000-2086_4-10050423&ontId=2086_4&spi=8a65787c3d716ade17cdd945236bcee4&lop=link&tag=tdw_dltext<ype=dl_dlnow&pid=13689355&mfgId=74601&merId=74601&pguid=U2ZR2AoOYIwAAFKwmY4AAABY&ttag=dl_dldirect&ctype=language&cval=en&destUrl=http%3A%2F%2Fdownload.cnet.com%2F3001-2086_4-10050423.html%3Fspi%3D8a65787c3d716ade17cdd945236bcee4%26dlm%3D0