The .NET updates are known to fail and how to fix is widely discussed. The quick fix is to uninstall the .NET that failed and reinstall it. However if you don't use .NET apps, why install it?

"Is it safe to download/install this update without any harm to my system?"

Sadly my answer must be no. Given today's malware we can't state that any changes are absolutely safe. This is why so much is written about backup and keeping the malware off the machines.

But has these updates bothered any of the machines at the office here? My answer is no. We have yet to see any issue. But in the real world and these forums you find folk that did have trouble.