From OpenHome
Click the following link:
Download, Open, Install this certificate into the automatically selected store
You should get 'Import was successful' dialog box
Then run mmc using Start-> then type mmc Then File->Add Snap-In -> Certificates ... for My User Account Then File->Add Snap-In -> Certificates ... for Computer Account
Then cut and paste the OpenHome Test CA certificate from: Current User -> Intermediate Certification Authorities to: Local Machine -> Trusted Root Certification Authorities