You will need
  • The Program Paint.NET
To reduce file size is usually reduced and the picture resolution. To change the picture resolution will require even the most simple graphics editor. For example, is quite rich on features, free Russian photo editor Paint.NET. You can download it here: Set Paint.NET takes up very little space on your hard drive, and its interface is comprehensible even for inexperienced user.
Install Paint.NET launch it, open the picture whose size you want to change. Go to menu "File" – "Open". After the picture opens, click on the toolbar "Image" – "resize". In the window that appears, select "Percent" to change the resolution of the image in percentage. If you want to pre-set resolution, such as 800 pixels wide, choose "Absolute size" and enter the desired parameters. Tick the option "Maintain aspect ratio" so that the picture is not stretched out and does not flatten.
The picture with the new resolution ready. In order not to lose the original file, which may be useful in the future, do not overwrite it, select "File" – "Save as" and save the resulting image with the new resolution in the desired format at any convenient location such as the desktop or in the folder "My images".