To add an SSL cert to IIS 5 on Windows, you need three separate steps:

  • Create a p12 (pkcs12) cert file:
cat server.key server.crt > server.pemopenssl pkcs12 -export -in server.pem -out server.p12 -name "server"
  • Import the p12 file into IIS:
Start->Run->mmcCtrl+MAdd...CertificatesComputer AccountFinishCloseOKOpen "Certificates (Local Computer)" treeRight click CertificatesAll Tasks->Import...Browse to .p12 certNextNextNextFinish
  • Select cert for site:
Open IIS AdminSelect properties of websiteSelect Directory Security TabServer Certificate...NextAssign existing certNextSelect CertNextNextFinishWeb Site tabSSL Port 443ApplyOK

Also if there isn’t separate IIS installed we can also attach the certificate from cmd:
Start / Run / cmd
List current certificates attached to the ports:
netsh http show sslcert
Add new certificate to a port:
netsh http add sslcert ipport=0.0.0.0:PORTNUMBER certhash=THUMBPRINT appid=GUID
PORTNUMBER: ipport=0.0.0.0: will remain untouched, just need to specify the port, for example:
ipport=0.0.0.0:443
THUMBPRINT: this is the thumbprint of the certificate. You can check this thumbprint by double click on the certificate in the certificate store,select Details, and “Thumbprint”. Use this without white spaces, for example: 42 b3 f1 c1 d1… will be 42b3f1c1d1…
GUID: this should be generated with Guidgen.exe .

Example command: netsh http add sslcert ipport=0.0.0.0:443 certhash=42b3f1c1d1c1fg8dd81sd1 appid={CJKC07D-8D1D-CCSa-CS1s-VSF1CS1dsX}