Hmm, this doesn't look good at all, so I would try to perform an in-place-upgrade at this stage.
- Mount the Windows Server ISO and run Setup.exe.
- Use the option Download updates, drivers, and optional features (recommended) and click Next.
- Depending on your Windows Server version and license, you may see a screen prompting you to enter the licensing key.
- In the next screen, select the image of the installed Windows Server edition and click Next.
- Then accept the EULA. To perform a in-place upgrade, you need to check keep personal files and apps. Then click Next.
- After clicking Next, an upgrade process will start checking for updates, when this is ready click install to start the in-place upgrade.