well, you are not really giving too much info.
Which wireless router do you have, which card? what software are you using to connect?
Not that it would help much, there are a lot of brands, some very good, some not so good, depends on the software.
Some times resetting the router (unplug the power) can help, is you keep getting problem, consult the manufacturers website, they might have a new firmware that could solve your problems, same for the wireless card.
Also, if the router is near a source of interference (like a refrigerator) or a computer you might have problems.
Depends also on where you live, there are areas where there is a lot of interference, like near an airport, and you might not be able to use a wireless router.
If that's the case, you might need to spend a few more bugs and go for a better router, such as Cisco (not a big one, they have some small models), but really, it's impossible to help, if you call technical service they would probably ask you which lights are turned on but that means different things in different brands.