Choose Internet Options from the Tools menu.
Click the Content tab.
Click Import to open the Certificate Import Wizard.
In the Certificate Import Wizard, click Next.
On the File to Import page, click Browse and locate the .p12 file, then click Next.
On the Password page, do the following:
On the Certificate Store page, choose the default, Place All Certificates in the Following Store (Personal), then click Next.
Click OK in the information dialog that appears.
The new certificate, with the first and last name you specified, appears in the Certificates window.
Click Close in the Certificates window.
Click OK in the Internet Options window.
After you import the certificate, you are ready to log in to the registry. See Logging In to the Registry for details.