if i make an other video, what i must do for video is HD because some players want HD .
Depending on your computer specs, record with the highest possible resolution, as long as it doesn't rape your framerate. For Youtube HD, your video resolution has to end with 720p or above. This means that, if you want youtube to display your video in HD, you've got to use a resolution such as 1280*720 ("basic" HD resolution). Youtube also supports 1080p videos but I doubt you can even display such a resolution
Also, on youtube, any resolution above 720p will also be considered as HD (for example, recording @ 800/600 will NOT be HD on Youtube; 1440/900 WILL be in HD, 1024/768 SHOULD be in HD [768 > 720, I never tried personally though ], 1600/1200 WILL be in HD, 1680/1050 WILL be in HD aswell.)
Hope you understood lol
Last note, the bigger your resolution is, the better your video quality is. NEVER resize your videos in Windows Movie Maker (because judging from the titles I guess that's what you used). Just watch out if WMM doesn't do it by itself to match some possible filesize criteria.
Et au pire si t'as toujours pas compris tu m'envoies un PM ici