When you find a vid you want .....
Let it run, to ensure you have a decent stream ( ie no 'buffering') - then ...
Copy paste the link from the 'url' box (top right) in Y/tubedownloaders 'Get Video' box - then follow prmpt to d/l.
The vid will appear on your desktop with the default icon - 'Get video,'
Should you want d/load more ... you will need to rename each of them 'Group - Title
.flv
FLV is Flash Video Format.
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To be sure they will play on your comp, download this ....
K-lite Codecs Pack ( Full Version)
http://www.free-codecs.com/download/...Codec_Pack.htm
Install. Reboot - and you should be, as you Yanks say, 'Good to go.'