Where can i find a software for capture a picture from video file for free ???

"google is your friend"

try a software archive, it can store thousands of softwares,
here's an example: http://freeware-store.com

Well if you're on a pc, then play the video in full screen in any video player until you get to the spot where you want to take the picture, pause it, press Print Screen (or PrntScrn), then open Paint, paste it, and save it.

If you're on a mac, open it in Quicktime, go to the spot you want to save as a picture, and then File>Export, and select Movie to BMP, and save it to where you want it.

With BlazePhoto, you can share your pictures in more place: html albums, CD, slideshow DVD, export to other folder, send to friends or family by e-mail, or print out for later sharing.

Powerful Photo Editor
Adjust the color and lighting aspects (brightness, contrast, hue, saturation) of your photo to produce a more visually enhanced picture
This photo editor is also powered by its multiple effects: blur/sharp, enhance effect (normalize, stretch or equalize), other special effects (emboss, gray, mosiac, motion, windy),
With this helpful photo editor, you can create unique images by adding text, clips, frame or use its powerful photo editing features like rotate, flip, resize, crop
Effective Photo Sharing Software
After you have finished to edit the pictures, you may want to share them with your friends or family
You can send the pictures in email message, or you can create the images as a html album for web sharing, burn pictures into a CD, make a photo slideshow DVD
Moreover, you can also choose to print the pictures out at home or office