1. You need to remote the old certificate. Search for 'Keychain access' in Spotlight and select it from the list.
2. Select your name from the list (it should look similar to the example below) and select Delete "your name".
3. Now you need to request a new certificate. Copy and paste this web link in your browser: centwsapps01.centaurgroup.private.co.uk/certsrv/. Under the Select a task subheading, click on Request a certificate.
4. Select User Certificate.
5. Make sure that key strength is 2048 (High Grade) and click Submit.
6. Select Install this certificate.
8. On the Add Certificates dialog box, click Add.
9. Now you can connect to the Wi-Fi! Click on the Wi-Fi icon from your desktop and select Centaur - Corporate Devices.
10. Enter in your Centaur username i.e. firstname.lastname. Click Join.
11. The Verify Certificate dialog box pops up. Select Continue.
12. Enter in your Centaur computer login password in the Password text field. Select Update Settings.
13. Click Allow.
14. Click Allow and you should be properly connected to the Centaur - Corporate Devices Wi-Fi.