how to install Certificate(.cer extension) in Windows 8 programatically?

Hi,

For which app are you installing the certificates?

Installing self-signed certificates for your Domain’s Certification Authority

In order for self-signed certificates to work, the administrator needs to provide a certificate file that will be installed on client machines that are to be connected to the server that uses self-signed certificates. The certificates need to be installed to the trusted root certificate authority store for either the current user (doesn't require admin rights but needs to be completed for each user on the machine) or the local machine (requires admin rights and needs to be done only once for a machine).

Important: The following section contains steps that require administrative privileges to perform. Serious problems might occur if these steps are performed incorrectly. Please make sure that you follow these steps carefully.

Certificates can be installed using the following means:

Command Line: Running the following from an admin elevated command prompt will install the certificate to the trusted root certificate authorities for all users using that machine.

certutil.exe -f -addstore root <name_of_certificatefile>.cer

User Interface:

1. Double click the certificate file provided by the administrator. This will open a certificate dialog.
2. From the Certificate dialog, click the “Install Certificate” button located on the general tab. This will open a Certificate Import Wizard Window.
3. Select the option to install the certificate for only the current user or for the Local Machine.
4. Select “Place all certificates in the following store”.
5. Click the browse button to open the store selection dialog.
6. Select “Trusted Root Certification Authorities”
7. Once the store is selected, click Ok. This will return you to Certificate Import Wizard dialog and will display the certificate store and certificate to be installed into that store.
8. Click finish to install the certificate.

Let us know if this helps.