Step 1 :Right click the certificate file and select 'Install PFX'.
The certificate import wizard starts
Click 'Next'
Step 2 :Enter the password that was given during export. Check the two options if required.
Click 'Next'
Step 3 :Keep the default option (the first one)
Step 4 :Click 'Finish'
Step 5 :Click 'OK'
If the import is successful then you will find this message.
Import the certificate From Internet explorer
Step 1 :Go to Internet Explorer. Select 'Tools' then 'Internet Options'.
Step 2 :Then select 'Content' and 'Certificate'.
Step 3 :Then select 'Import'. The import wizard will start. Click 'Next'
Step 4 :Click 'Browse'.
Choose the Location where you stored the certificate file. Here we stored the file in desktop. After choosing the location you may not be able to find the certificate file. Select the file type “Personal Information Exchange (*.pfx*, p12)”,as shown.
You will now find the certificate file stored in desktop. Here we find the certificate file
named 'Ashok_karania'. Select the file and click 'Open'.
You will again come to this window. Click 'Next'
Step 5 :Enter the password that was given during export. Check the two options if required.
Click 'Next'
Step 6 :Keep the default option (the first one)
Step 7 :Click 'Finish'
Step 8 :Click 'Ok'
If the import is successful then you will find this message.
After installing the certificate you need to install the MTNL Trustline Hierarchy
certificate. This will authenticate your certificate.
MTNLTrustlineHierarchy certificate Installation
Step 1 :Go to the following link and download the MTNLTrustlineHierarchy certificate.
http://www.mtnltrustline.com/hierarchy.htm
Step 2 :Right click on MTNLTrustlineHierarchy folder and select 'Install Certificate'
Step 3 :Certificate import wizard will run. Click 'Next'
Step 4 :Click 'Yes' and the Hierarchy certificate is installed.
MTNLTrustlineHierarchy certificate is now installed to your browser.
Step 5 :Click 'OK' 
