check the wireless range of your modem, even if given by singnet, the packaging outbox should have the hardware details.
if out of range can cable the wireless modem to the best central position of your semi detach so all other pc/ connection with wireless card are in range.
but i doubt so since unlike cable, wireless modem offers several feet/ metres of omni-coverage unless u may have devices causing interference? improperly shield equipment, acrylic case computer, bass/ subwoofer unit of speakers which are usually not shielded etc...
or else......


