I am having a issue with new windows 8.1, it was all working fine few days back then of a sudden some applications, like calendar, Bing Finance, Mail when clicked automatically minimizes on the taskbar. It looks like it has lost focus and is not working. I have tried suggestions on multiple threads, none of them work. I understand there might be a third party application doing this and most probably it is the Dropbox that is doing this. However i have tried clean boot and system restart with safe mode, none of which has resolved this issue. On the same system i have an another user account, this account has no such issues. every application works and opens fine. I am not sure what went wrong in my primary admin account. Can anyone help me with this issue.