Should I install the Microsoft .NET updates?

I’m not really sure if I need to install the Microsoft .NET Framework 3.5 Service Pack 1 and .NET Framework 3.5 Family Update (KB951847) x86 update.
It shows up in Automatic Updates and seems to be rather large.

I’m not a programmer and really don’t know who/what uses .NET.
I manage a 50 station network with an Apple Xserve, take care of their websites, and do multimedia work.

Thanks for the advice.