As the Youtube Video Downloader, HiDownload is quite easy to use. Just copy the flv video's URL from Youtube, and paste it to HiDownload window. HiDownload will automatically analyse data and get the actual URL, then download flv video file to your PC.
Hidownload Features
Support online download video, audio and more
First-class streaming video and audio downloader supports a variety streaming file formats on more websites.
Keep original streaming formats with highest multimedia quality
Maintain the original streaming formats for downloaded files. By using advanced downloading technology, Hidownload is a more comprehensive way to get highest quality streaming file.
Easy to use
Easy to use, it doesn’t even need you to do anything, just visit or reload the webpage while Hidownload built-in Sniffer is running; if you prefer a video in the case of Sniffer Off, a youtube video link/URL almost can solve everything.
How to download youtube flv video by HiDownload
Step by Step Instructions
1.Download and install HiDownload Platinum.Run the software
2.Open the Youtube website.
3.Right-click the flv video. Select "Copy link address" (Google Chrome) or "Copy Shortcut"(IE) mene or "Copy Link Location"(FireFox)
4.Return to Hidownload, click the "Add" button 
, paste the youtube link address in the "URL" editbox, and the stream automatically becomes "Flash Video Streaming".
Note: You can directly tag/rename the file name before it's downloading.
5.Click "OK" button, HiDownload will start to download the flv video file.