It sounds to me like the libvlc.dll file isn't registered which is why you keep seeing the message that it's missing even though it could well be present in the appropriate directory.
You didn't mention whether you have the 32-bit version of the VLC player installed, or the 64-bit. I'm going to assume that it's the 64-bit so do the following please.
- Hit Windows key + R to open the Run command.
- Copy/paste the text in bold type and click OK: C:\Program Files\VideoLAN\VLC
By the way, in a command prompt window you have to right click and paste. In that respect CTRL+V doesn't work.
- Check to see whether libvlc.dll is present in the directory which opens.
- If it's there close the directory and then right click the Windows Start button and click "Command Prompt (Admin)". This will give you a command prompt which looks like this: C:\Windows\System32>
- Since the dll file isn't present in the System32 directory, you have to change the path to match the location where it actually is. So type: CD\ and hit Enter.
- You should now be able to see just a C:\ prompt which looks like this: C:\>
- Copy/paste: CD C:\Program Files\VideoLAN\VLC and hit Enter.
- At the C:\Program Files\VideoLAN\VLC prompt, either type, or copy/paste: regsvr32 /u libvlc.dll and hit Enter. You might see a message that the file was unregistered.
- Next type, or copy/paste: regsvr32 libvlc.dll and hit Enter. You should get a message that the file was successfully registered.
- Type: EXIT to close the command prompt window and reboot the computer.
Try and open vlc and play something.
Even though the libvlc.dll file is present (presumably) it's still important to unregister it which is what the regsvr32 /u libvlc.dll command does in order to clear anything which might be causing Windows not to be able to find it.
If you have the 32-bit version of vlc installed, type or copy/paste C:\Program Files (x86)\VideoLAN\VLC as appropriate instead. Otherwise all the commands are the same.
If you get an error message performing any of the above commands make an exact note of it without paraphrasing and post it here please.
I'd also recommend you download the free version of
Malwarebytes and performing a Threat scan (you'll see it on the menu). Delete anything it finds.