A couple things you can try.
1. Google "how to boost wifi" and check youtube as well as Wiki-how-to.
It amazed me to find FREE and SIMPLE home made ways to boost your routers signal (and it works).
Also, you may need to just move the position of your router/its antennas.
Also, other wireless devices (and microwave ovens ...... Basically anything electronic with emissions) near or between your router and palm/laptop/phone (whatever) can greatly affect signal strength (as well as give you a mental jolt of reality about how many wireless and other emissions we live with every day)
Finally (actually there are tons more suggestions from a simple Google search ......
freeantennas.com has a "template" which you can print out, trace on stiff paper and make a virtually free antenna booster (plus a little glue and tinfoil)
For the very lazy (I found out) a curved piece of cardboard (covered in tin foil even better) behind your router's antenna directing the signal in the direction of you device can DOUBLE the signal strength (I was amazed as a klutzy non-techie with lazy tendencies)
