Explanation
A S.M.A.R.T. error is a warning that a hard drive is about to fail or has failed. This means that the OS cannot be loaded from the drive and the user will see an error message indicating there is no OS found. The most likely cause of this issue is drive failure.

Explanation
EOL (end-of-life) is a term that indicates a vendor no longer supports a product. It means that the product will no longer be sold, updated or patched by the vendor, and that the users should migrate to a newer version or alternative product. AUP (acceptable use policy), EULA (end-user license agreement) and UAC (user account control) are not terms that indicate a vendor no longer supports a product. Verified References:
https://www.comptia.org/blog/what-is-end-of-life https://www.comptia.org/certifications/a

Explanation
The newly installed OS is x86. The x86 version of Windows 10 can only use up to 4GB of RAM. The x64 version of Windows 10 can use up to 2TB of RAM