How Install .Netframework 3.5 SP3 KB979909 & KB982157

I keep getting presented these updates and they always fail to install.
I do not know what they do. Do I need them or would the best solution be to
hide them?

My System XP_Pro_SP3 and OFFICE_Pro_2007 otherwise fully updated

You could try installing them manually after downloading from the MS
Download Center.

I, also, keep getting these updates and they will not install. I figured
since they were from Microsoft, they were legit. Every time I turn on my
computer, it tells me there is a problem with an undate. How do I hide them?

Concering Hiding updates at least on an XP system it is easy but i only reccomend doing so if you truly beleive you do not need or want the updates...it always best practice to use/get all security updates as these are...but here's how

Double click on the yellow shield in your taskbar -> choose "Custom Install (Advanced) ->Click "Next" -> then uncheck the boxes next to the updates you do not want -> Click "Install" -> you should then have an option box to check to "Don't Notify me about these updates again" -> click ok. Continue installing any others you may have/want....doing this will in effect hide the updates you do not want.

If you choose later that you want the updates you can unhide previously hidden updates from the microsoft update center via I.E. tools menu!