As a computer tech who works on computers and have seen this exact problem several times before, I can tell you it's honestly pretty simple to remove Vista antivirus 2011 (or it's many variants).
You'll need two programs. One is the previously mentioned MBAM. The second you'll need is called RKill. Pick up the explorer.exe version (I'd post a link, but I'm not allowed as a new user).
Run rkill on your computer (regular mode, not safe mode). It might take a bit and pop up a black window or two. This is normal. Once it's done, start up MBAM and let it update (if it doesn't update, as in not able to connect online, you HAVE to do it manually. Otherwise it won't detect the virus). After the update, start a full system scan.
After a half hour or so, it should be done (mattering by your computer speed largely) and it should show a list of malware. There should be about a half dozen or more files. If there's only one or two, you probably need a more recent update. Either way, let it delete everything listed. Once done, restart the computer and if all done right, you'll be set.
As far as preventing it coming up again, you're probably getting it from a usual source. Email, certain downloads and websites, messenger services. Consider where you have questionable connections in the past and reconsider using them.
Hope this helps.
