How to edit registry to delete malicious computers on network

Hi - Stupidly clicked on rogue email attachment two days ago; have run Microsoft virus scans, etc., but nothing shows. However, an unknown computer (two today!) is showing up in my network area.
Have disabled as best I can all network/file sharing and have mostly had computer unconnected to Internet.
Is there any way to go into the registry and delete malicious remote computers?
If so, will that solve my problem or should I wipe machine and reinstall software?
Would prefer not to have to reconfigure computer, as I haven't been backing things up adequately.
Thanks.

Do you have a System Restore point to a date before this started--like to May 11 or May 7?

Have you downloaded and run a malware scanning tool such as Malwarebytes?

Are you using WiFi by any chance? If so, I would change the password as there is a chance of neighbors entering it to use your internet connection. This has nothing to do with viruses really.
The registry is neither important for remote computers.

But if you really have a virus, look at your process list, see if there is something strange there. If that's the case, the only 100% safe way is to reformat of course, but many other cleaning procedures can be done too.

Thanks for the reply. Ran Microsoft Malicious Software Removal Tool; should I run Malwarebytes as well? Will try System Restore to May 10.
Yes, am using Wifi (WPA-2?) but doubt that's the problem - computer acted weird as soon as I clicked on attachment and I'm pretty sure I have a virus/trojan problem. Will have a look at process list once system restore finishes - thanks.

I would still change the password. It may not be related at all, most likely, but there is a chance that you just discovered a completely unrelated problem just by coincidence, that others are using your network though WiFi without you noticing. And neighbors using unsecured WiFi is not something unseen.
That also doesn't depends on anything on your computer. I would do it just to be sure.

Update: System Restore seemed to zap my suspicious computer network buddies and I plan (finally) to back up my files. Thanks so much for the help! Might run Malwarebytes, too, just in case.

I'll change the WiFi password, too - thanks for the advice!