WiFi signal of my Zyxel P-660HN-T1A (ISP provided) gets weak when I go 2nd floor of our house. I have an extra router (Linksys WRT120N) and plans to use it as secondary router to boost signal. However, I do not know how to configure it as I am ot a computer savvy. Please help me. I am using an ASUS Transformer TP300LA (no LAN port and optical drive). OS in use: Windows 8.1 SL.