I cannot detect my router

A first logical step would be to take your laptop to another wireless location and see if it will work there (you could also take the your wireless unit there to test it). Likewise invite a friend with a wireless enabled machine to visit you and see if they can see your wireless unit. There are three different types of wireless devices in common use A, B, G you need to know which your machine uses and which the wireless receiver uses and assure there is a match. Some devices support multiple types A&G, B&G and A&B&G as long as one matches between the wireless adapter and wireless router/access point assuming the others were not configured off the test should be valid.