回复：laptop wireless connection

using external wireless card may not help as dell already has built-in wireless antenna(s) connected to your mini-pci 2200BG card.
the physical distance and obstacles in between usually are the problem.
wireless access point and router may also have more or less compatibility problem with wireless card
monitor signal strength at one location and see if it changes over time. If it does, pick another channel and find out if there are other 2.4GHz devices in use (cordless phone, microwave)
If it doesn't, you have to move close to your access point or buy a signal boost antenna for the access point.