Tried with different channels but of no use

I am able to connect router on windows 7 and Android. But if router is switched off and again switched ON ,SSID is visible on windows 8 but not in windows 7 and Android phone. I have to use cable or...

Region : India Model : TD-W8151N Hardware Version : V3 Firmware Version : ISP : BSNL Works ok with Windows8.But has to save wireless configuration for working on Windows7 and Android after switching...