LapTop Wireless Antenna

Well, an antenna is a bit more than two pieces of wire. Just linking two pieces of wire to a transceiver is an excellent way to get a poor signal. I'm assuming you tried to make a dipole antenna.

There's a small bit of simple math here (for the dipole, at least).

You'll need the frequency your router transmits at, which we'll make equal to f.
You can then calculate the wavelength of the transmitted wave by this equation:

w=(c/f)

whereas:
w = the wavelength of your radio wave, in meters
c = the speed of light (an electromagnetic wave, in a vacuum, which is constant at 2.998x10^8 meters/second)
f = the frequency of the wave, which your router can tell you (it is likely to be 2.4GHz)

Then, once you have the wavelength, you can calculate the proper length of each leg of the dipole antenna by dividing the wavelength by 4 (for a quarter-wavelength antenna, at least. You may divide it by any factor of 2 (half and quarters are most common), but your signal quality will differ each time - you'll have to balance size and quality).

For more information, head here:
http://en.wikipedia.org/wiki/Dipole_antenna

EDIT: and if you did that already and didn't post it, no insult to your intelligence!