Download a freeware, which turns out to contain malware. How to remove?

Get some anti-virus or anti malware and clean your computer.

I would do a search for Vosteran search and read up on a few or more “how to’s” for removing that bugger.

I would then run an antimalware program after to make sure nothing else in hiding in my computer. I use a freeware called malwarebytes that seems to do a good enough job of cleaning things up.

@Cruiser is right: run a third party anti malware program (Malwarebytes is the best free one I have ever used) to identify and eradicate any malware that has crept in.

However on my laptop I go further in two ways:
first, I also have AVG anti virus installed (it’s free also, except I did upgrade to AVG Internet Security Suite in order to gain a third party firewall). In a case where one program installs another without permission, there is a good chance you also picked up at least one virus as well, which is where AVG becomes essential.

Second: all legitimate software gives you the option of saving downloads to a specified file (Windows Downloads folder is easiest to use) and install later. I always click on “Save” instead of “Run.” This way, by hovering the cursor over the downloaded file and right clicking, you open up a floating menu of options. Clicking on “Scan with AVG” alerts you to the presence of any possible virus infections before you launch the installation process.

(Disclaimer: for a long time I didn’t pre-scan downloads for problems for a long time. However, back in October, I tried to install some free fonts downloaded from the website that appeared at the top of a Google search for Windows 8.1 free fonts. What I ended up with were: 6 unwanted programs, 9 viruses and 0 fonts. Lesson learned.)

Depending on your OS, you can find a restore point closest to the day you got the malware and restore the system to that point and the malware will be gone. Malwarebytes or Spybot, I found good at removing them. I would also use Revo Uninstaller to remove the malware or the VLC player and all files associated with it, even the registry keys, which should kill off the problem. Or do a search by date, anything added to the system the date you got the malware, delete it, chances are one of those files is the malware.