How do I get rid of a virus on my laptop?

[Expertbrush984]

Plus HD 2.2 somehow got onto my computer a whiiiilllleee ago. I knew it was an unwanted program, but didn't know it was the one causing the ads and whatnot. So i tried to delete it a few months ago by going to control panel- programs- and uninstall. But it windows wanted to uninstal it all manually with this full scan where my computer turned black with white letters. I was fine with that as it was going to get rid of the PUP, but it was taking WAAYY too long and i had home work i really needed to do. So I stopped the scan.

Now the virus is really bad and i understand my mistake in not getting rid of it sooner. I can't simply go to Uninstall a program and uninstall it. It doesn't work. Nothing happens. What can I do to get rid of it? I tried Windows Defender scan but nothing happened, it just said "Scan complete". I am not super good with computers that i trust myself with a bunch of command prompts but I am skilled enough to try other things.

I have Avast Antivirus on my computer, and whenever I go on a website it says "Malware blocked" But, really, it is not blocked as I see all the ads and the site does not work properly. Also, whenever I open Google Chrome, another page opens up with the harmful website caused by the virus. I always just close that window but it is extremely annoying and unsafe.

I use Windows 7 with Intel core i5 on a Vaio computer if that is any difference. Please help me and (PLEASE) if there is a non-complicated way I'd love to hear it.