How to Change VLC to WMP?

have used and windows media player for a long time and like it, but I downloaded vlc so that I could watch a video that wouldn't play on WMP. It ended up changing every video I had loaded on my computer to VLC media files. I don't want VLC so I deleted all VLC files and uninstalled the program, but every time I download a video it says VLC media file and when I try to play it through windows it says that windows doesn't recognize the extention .flv. I had no problem with this before I downloaded VLC. How can I get Windows Media Player Back!?