Windows Defender couldn't check for virus and spyware definition updates. Check your Internet or network connection and try again.
I was wondering why am getting this kind of error while trying to update the Windows Defender.
So, after some digging into web search and came to know that the Windows Defender got corrupted.
How the hell that happened. No hope ...
1. Only solution is to reinstall your Windows 8 OS.
2. The other is a workaround by running the definition file.
But the disadvantage is every time you need to download the definition and run the installer.
So I download and Install the latest Microsoft Security Essentials definition updates. Done, the definitions got updated.
Microsoft website says,
"By default, Microsoft Security Essentials is designed to install and run updates automatically. If you have disabled this feature or if you encounter problems updating automatically, you can manually download and install the latest Microsoft Security Essentials definition updates for your computer."
Even the website having the latest virus definition definition and released information.
So, download : mpam-fe.exe from Malware Protection Center and run the installer.
At last, Windows Defender is happy now !