NOD32 can't find server and I can't get on ESET website

About a month ago I downloaded a trial version of NOD32 on all three of my computers, 2 desktops at different locations and 1 laptop. I have since purchased a license for all three machines and have successfully activated the license on 1 desktop and the laptop. But my other desktop trial version has now run out and I'm trying to upgrade to the licensed version. I've put the username/password in, but NOD32 says the upgrade failed. I've also attempted to go to www.eset.com and my machine won't find the website. I have pinged the site and the ping says it's there and I can certainly get there on my laptop, so it's got to be a problem with my desktop. In the last few weeks I've also been getting pop-ups, even though internet explorer pop-up blocker is on and it says it's blocking the pop-ups. Not sure if these two things are related.
I've flushed the dns and I've checked my HOSTS file and there's nothing in it except my local host. These actions were suggested on Leo Laporte's forum, but I've had no luck.
I uninstalled NOD32 a few minutes ago hoping that would correct the problem, but I still can't connect to ESET's website. This apprears to be the only website I regularly visit that I now can't get on. Please help me.
Thanks in advance.

Well, it seems my machine was terribly infected. It would also seem that Windows Defender is useless, as it never found a single instance of spyware. I think I'll uninstall it.
I tried about 5 different programs before I finally stumbled upon Malwarebytes and this thing found 51 spyware/malware/registry problems/dns changers etc. Not sure how this happened, but I just hope it was because I changed my antivirus to NOD32. Would love to hear any comments or suggestions to avoid a repeat.