Step 1: Click “Add File” button to import your videos from your computer.
Tips: Click a file in the list and you could use the preview control buttons to play the file.
Step 2: Click "Format" combo box to select the output format, such as to mp4 for iPod, iPhone, Zune, PSP, Creative Zen, Blackberry, Nokia, Apple TV, etc.
Step 3: Click “Convert” button to start conversion. The conversion will be completed in a short time.
Ok, now you have converted your MKV files to other format files and you may use it more convenient.
Tips:
1: How to crop off the black edges and adjust the size of video play region
By using the "Crop" function you can crop off the black edge of your video and you can also drag the line around the video image to adjust the video play region to fit for your mobile devices。

2: How to change your video effect
If you want to adjust the effect of your movie, please click the “Effect” button and a pop-up effect window will appear. It allows you to edit your movie’s effect including “Brightness, Contrast, Saturation and Volume”.

3: How to split or join the videos
Click "Trim" button and you will see the trim window. You can move the slide below the screen or enter the start time and end time on the right to get any segment of the video. The blue line part is the video you will get.
And if you would like to put several files into one output file, please tick the check box of the “Merge into one file”.

4: How to save your favorite picture
If you like the current image when preview video, you can use the "Snapshot" option. Just click the "Snapshot" button, the image will be saved and you can click the "Open" button next to "Snapshot" button to open your picture.

Code:

http://www.nidesoft.com/downloads/mkv-converter.exe.