Outlook, being a Microsoft product attracts a lot of credibilities and that’s one of the reasons most people rely on this email service. Your Outlook won’t open due to several reasons like Outlook email login issue, entering a wrong email ID password, accumulation of junk files in browser history, or sometimes the virus or malware attack also becomes a culprit in Outlook not opening problems. However, with problems comes the solution as well and the above-said problem can also be resolved using some specific measures. You may try to reset the navigation settings and for that firstly, you will need to open the run command by pressing Windows + R keys. Once the Run dialogue box opens, type Outlook.EXE/resetnavpane and Hit enter. Even then if the problem doesn’t resolve, you should try to run the antivirus scan. Make sure to install the authorized antivirus program on your computer, scan your PC for any suspected virus or malware activities and let the application fix the problem for you. If Outlook still won't open, then you should contact the Outlook experts for further assistance.