It is recommended that for use of the administration module of the system you use the Google Chrome browser. If you do not have to chrome browser yet on your computer you can download it for free: https://www.google.com/chrome/browser/desktop/index.html
The chrome browser is a light weight but powerfull browsers that works good with the administration module. Other browsers like Firefox, Internet Explorer or Safari also work with the administration module but chrome gives the best performance with the system.