Recently I tried to install a [fake, yep :P] computer game on my computer and as soon as I tried to play it, a message started to appear in the tray icon area of the taskbar saying that my Xvid codec was outdated or broken and that I needed to downloaded a updated version. Since there're some videos on the game I thought it was legitimate - the message that appeared even sad that it was Windows the one who detected the problem. Then I clicked in the tray message and a Windows popup appeared repeating the message and asking if I wanted to download the updated now. I clicked "ok" and then I was redirected to a invalid website called "http://www.xvidcodecsdownload.com" (or something like that). Since that website was invalid, I looked for the Xvid website on the net and manually downloaded the last codec pack, but that didn't stop the message from appearing (needed to reboot? maybe I forgot to do that...). I then uninstalled both the computer game and the Xvid codec, but the message didn't stop appearing. It's also interesting that, if I noted correctly, after a system reboot the message don't appear, than it start appearing frequently and in some cases, just before the message appearing, a weird thing occurs with the screen when the image get distorted.
I began to think it's a virus and I'm doing a whole virus scan in my computer now. But while I was searching on my computer for the explanation of what is actually going on, I wen to the task bar icon tray area and noticed the particular figure of the icon displaying the messages and entered in the configuration of those icons and found out that the thing telling me those messages was called "Windows Host Error Reporting Service".
I did a search in the web about this "Windows Host Error Reporting Service" and no track of its existence was found. After rebooting, I noticed that it appears now just at Window's start and then I went to msconfig.exe and the closes thing I found with a related name was "Windows Error Notification Service", a thing about which I couldn't find anything on Google either (only things about a "System Event Notification Service".
I would be glad if someone could explain to me what this thing is - and if someone wants to comment about the general problem as well, feel free!