Windows 7 - long distance wifi

In the summertime I move my computers into a converted barn office space. I am using a dlink wireless router (DIR 601). I would like to use my notebook in the house at night so I need an antenna of some sort to extend the range from the barn to the house. The distance is about 100 feet and the house has steel siding on it. The house and the barn connect to the same electrical box at the pole but have separate breaker boxes. The lights can go out in the house and stay on in the barn. So, I am assuming the plug in whole house antennas that are advertised would not work. I have one dsl modem from the ISP and I do not want to pay the ISP for another modem. Win 7, 64 bit.
Any suggestions? Thank you.

you can buy range extenders that basically accept a wireless signal in range and re broadcast it again. not sure if this will work for you. you need to find a spot safe from elements, with power within range of router and that will broadcast to your barn. or, pass a long ethernet wire to another router or range extender.

you could also try something along the lines of Lanshop - D-Link ANT70-1000 High Gain Dual Band Wireless Network Antenna depending on your budget, I have tried a cheaper version with some success it very much depends on the ammount of solid structures (trees, walls, fences, scaffolding) between the AP and the laptop. I put a lower gain AP transmitter outside my house for long garden range and then use Cat5 to my machine. wireless devices still worked fine inside and I had excellent range outside too (double compared to AP's original location about 3ft away but inside the house).

Hi Crank,

Might be cheaper to replace that 1 External Antenna for a High Gain Antenna similar to this one. Please read the technical details and make sure that it will work on your router.
A Wi-Fi adapter with high-gain antenna for your computer is also a doable option.

Other previously suggested devices are all excellent options as well.

Agree with 2xg, it really depends on your site layout. Lower budget solutions can be effective! although there may be reduced speed! It's a matter of weighing up you demand, are you just ocasionally browsing or transferring files over VPN and downloading etc. Against the cost. 100ft isnt too great a distance at all, if you get any accesspoint antennae outdoors (not much gain needed) it should work. A few points to remember: does your access point have interchangable antennae or are they fixed/internal? you may need to improve the antennae of the machine too to get effective 2way communication or infact establish a connection at all (not just detect it). Also should you choose a wired option e.g run a piece of cat5 to the barn, you have upto 90meters max cable length and you cannot run alongside power cables for any significant distance (e.g. dont just zip tie it to the power lines).