During the installation of the agent on Windows XP, the following error is prompted:
A required digital certificate is not installed on this machine.
This error is prompted due to required root certificate being absent on this machine.
The workaround is to use a modern web browser to access Acronis CDN and download the root certificate manually, import the certificate, and then rerun the installer.
Follow the steps below to manually download the required root certificate.
1. Download the latest supported version of Google Chrome web browser (ver.49) for Windows XP from archive.org and click Show all files.
2. Using the Google Chrome web browser you downloaded, go to the Acronis CDN page.
3. Click the padlock icon of the Chrome address bar to access the certificate.
4. Click the Details link. Ignore the invalid certificate message.
5. The certificate error is shown. Click the View Certificate button.
6. In the Certificate window, go to the Certification Path tab and select the DigiCert Global Root CA root certificate, then click on the View Certificate button.
7. In the new Certificate window, select the Details tab and click the Copy to File button to export the certificate.
8. On the Certificate Export Wizard page, select Cryptographic message Syntax Standard - PKCS #7 Certificates (.P7B) and check the Include all certificates in the certification path if possible option. Click Next to proceed with exporting the certificate.
9. After performing the steps above, you will have an exported root certificate you need to import into Windows XP. But before that, you have to add the certificate snap-in into the Microsoft Management Console (MMC). Type "mmc" in the Run dialog and click the OK button.
10. In the MMC console window named console1, open the File menu and click Add/Remove Snap-in.
11. Once the Add/remove Snap-in dialog appears, click the Add... button.
12. In the Add Standalone Snap-in dialog, select Certificates Snap-in and click the Add button.
13. In the Certificates snap-in dialog, select the Computer account option and click Next to proceed.
14. In the Select Computer dialog, select the Local Computer option and click the Finish button.
15. Returning to the Add/remove Snap-in dialog, you can see that Certificates (Local Computer) is added. Click the OK button to confirm.
16. Now you can import the root certificate for Acronis CDN. Expand the Console Root tree control until you can see the Trusted Root Certification Authorities node, then right-click it to open the drop-down menu. In the menu, open All tasks and click Import on the submenu that appears.
17. Once the Certificate Import Wizard opens, click Next to proceed.
18. Click the Browse button, then navigate to and select the exported root certificate that you obtained in Steps 1 to 7. Once you have the path to the certificate in the File name: field, click Next to proceed.
19. Select the Place all certificates in the following store option and make sure it is set to Trusted Root Certification Authorities. Click Next to proceed.
20. Click Finish to import the certificate.
Now the required root certificate is in the Windows XP certificate store and the certificate issue should be fixed. Please close the Acronis agent installer if it is still running and rerun it.