How to connect Lyx and SumatraPDF

Sumatra PDF is a lightweight and open source PDF reader. Lyx is a good Latex editor and easier to use.

To connect Lyx and Sumatra, the processes is as follows:
1. Open Lyx, Tools-->Preferences-->File Handling-->File formats-->Format-->PDF (pdflatex)-->Viewer-->Custom, paste the path of SumatraPDF into the textbox (e.g., "D:\Program Files\SumatraPDFPortable\SumatraPDFPortable.exe"). Note that "" is very important on the path.