Windows files opening on single click and underlined

Problem Description

Recently Ii had an issue with my Windows 7 desktop. All my files were opening on single click rather than double.Also I noticed that all filenames in my system was underlined

Fix

1. Browse to Control Panel -> Folder Options.

2. In the GeneralTab -> Click items as follows section, select Double click to open an item (Single click to select) option -> Click OK.