I had to modify this slightly to be used on a Windows System. Here's the one-liner version for a windows box.
openssl.exe s_client -connect yoursitename.com:443 > CertInfo.txt && openssl x509 -text -in CertInfo.txt | find "Signature Algorithm" && del CertInfo.txt /F
Tested on Server 2012 R2 using http://iweb.dl.sourceforge.net/project/gnuwin32/openssl/0.9.8h-1/openssl-0.9.8h-1-bin.zip