WordPress is the most effective content management system. It really works great and make the life easier for a non-techie blogger. You can setup it without having any technical background. Sometimes it can create few little problems like upload a large file or video. Increasing an upload file size can be a problematic thing if your WordPress is installed on windows. Many forums say that you only have to change the value of upload_max_filesize but it will not change the upload size in WordPress media. You have to make changes in the php.ini and make sure you set the appropriate values for under given directives.
upload_max_filesize = 100M
post_max_size = 100M