IP Addresses - Unwanted Remote Access

I talked to Microsoft on an issue and told them I used a wireless connection on one of my two computers. One computer uses Vista (wireless) and the other Windows 10 (through a router). Microsoft said my issue could have been caused by someone remotely accessing my computer. He then pulled up a screen that listed the IP addresses of possible computers that had accessed my computer. He offered to fix it somehow. I declined.

Anyway, how can I view IP addresses that have accessed my computer or network? And, is there a way to secure my PC from unwanted remote access.

Thanks,
Jerry
10/2/19

Hello bro67 –

To your question about my issue, I now think I was spammed. I received an email saying I had installed MS Defender Firewall on a trial basis and would be charged $1299.99 unless I called a number and cancelled. I called and the person showed me on the computer where MS Defender Firewall was running. He then proceeded to remove the software. It took a long time to remove, which made me suspicious.

So, I hope now I didn’t mess up my PC. I did create a Restore point before anything was done. Do you think I should restore?
Jerry

Clean install, contact your bank to stop any payments and change your credit and debit cards.

Thanks bro67. I will proceed with your advice.

Jerry