You can install each patch individually, or here's the link for the Security Update for Win 7 (KB4012122) that includes all the updates listed in the link above.

I did it and it worked fine. No problems, and it hasn't asked me to upgrade to Win 10.

I used the top choice, but check your system first.

[link to www.catalog.update.microsoft.com]

If you still want to go with installing them individually, the critical one in the first link is MS17-010.

I probably will switch to a another operating system when I get a new laptop. This one is so old, it's on it's last little ones and zeros. Changing now would probably smoke it.