Agree that you need to update and get all the securuty updates installed.
What is happening when you attempt to download and/or install the updates?
Are you receiving an error message? Some updates, such as Service Packs may have to be downloaded/installed independently of other listed updates.
I was at my wits end awhile back when I had very similar issues with obtaining the latest updates from MS.
I actually contacted MS via their support site, described in fairly good detail what I was attempting to do, what was happening, what I was seeing and any applicable error message received.
MS surprised me with their prompt response and after I believe one additional contact to clarify some item(s), they emailed me a detailed Step by Step procedure to remedy the issue.
Additionally, the person "handling" my request requested my feedback on the fix etc and was very helpful throughout the process.
NO CHARGE FOR THIS SERVICE.
You may want to give them a try: Microsoft Support