Check your firewall settings.

What firewall settings should I check in particular, and what else might I do?

in command prompt type ipconfig /all and post result here, it may help to determine what is wrong.  Just as a matter of interest can that laptop get to the internet via ethernet?

Sorry, I could not log in under the same account, but I am the same person! Here is the IP config information, and yes it can connect via ethernet. 

After reinstalling the Wlan driver, the wireless network will sometimes appear, but it will never connect.

Microsoft Windows [Version 6.0.6001]

Copyright (c) 2006 Microsoft Corporation.  All rights reserved.

C:\Users\Rebecca>ipconfig/all

Windows IP Configuration

   Host Name . . . . . . . . . . . . : CLIFFORD

   Primary Dns Suffix  . . . . . . . :

   Node Type . . . . . . . . . . . . : Mixed

   IP Routing Enabled. . . . . . . . : No

   WINS Proxy Enabled. . . . . . . . : No

Wireless LAN adapter Wireless Network Connection:

   Media State . . . . . . . . . . . : Media disconnected

   Connection-specific DNS Suffix  . :

   Description . . . . . . . . . . . : Dell Wireless 1390 WLAN Mini-Card

   Physical Address. . . . . . . . . : 00-1E-4C-82-33-E9

   DHCP Enabled. . . . . . . . . . . : Yes

   Autoconfiguration Enabled . . . . : Yes

Ethernet adapter Local Area Connection:

   Connection-specific DNS Suffix  . :

   Description . . . . . . . . . . . : Marvell Yukon 88E8040 PCI-E Fast Ethernet

 Controller

   Physical Address. . . . . . . . . : 00-15-C5-86-A1-28

   DHCP Enabled. . . . . . . . . . . : Yes

   Autoconfiguration Enabled . . . . : Yes

   Link-local IPv6 Address . . . . . : fe80::ace7:6406:8fb0:399f%9(Preferred)

   IPv4 Address. . . . . . . . . . . : 192.168.1.103(Preferred)

   Subnet Mask . . . . . . . . . . . : 255.255.255.0

   Lease Obtained. . . . . . . . . . : Friday, July 31, 2009 8:07:33 AM

   Lease Expires . . . . . . . . . . : Saturday, August 01, 2009 8:07:33 AM

   Default Gateway . . . . . . . . . : 192.168.1.1

   DHCP Server . . . . . . . . . . . : 192.168.1.1

   DNS Servers . . . . . . . . . . . : 66.82.4.8

   NetBIOS over Tcpip. . . . . . . . : Enabled

Tunnel adapter Local Area Connection* 6:

   Connection-specific DNS Suffix  . :

   Description . . . . . . . . . . . : Teredo Tunneling Pseudo-Interface

   Physical Address. . . . . . . . . : 02-00-54-55-4E-01

   DHCP Enabled. . . . . . . . . . . : No

   Autoconfiguration Enabled . . . . : Yes

   IPv6 Address. . . . . . . . . . . : 2001:0:4137:9e50:1840:ca03:bcd2:d2f6(Pref

erred)

   Link-local IPv6 Address . . . . . : fe80::1840:ca03:bcd2:d2f6%8(Preferred)

   Default Gateway . . . . . . . . . : ::

   NetBIOS over Tcpip. . . . . . . . : Disabled

Tunnel adapter Local Area Connection* 7:

   Media State . . . . . . . . . . . : Media disconnected

   Connection-specific DNS Suffix  . :

   Description . . . . . . . . . . . : isatap.{BF6718FB-E315-45D0-B216-9BE08CFE8

3A4}

   Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0

   DHCP Enabled. . . . . . . . . . . : No

   Autoconfiguration Enabled . . . . : Yes

Tunnel adapter Local Area Connection* 9:

   Media State . . . . . . . . . . . : Media disconnected

   Connection-specific DNS Suffix  . :

   Description . . . . . . . . . . . : Microsoft ISATAP Adapter #2

   Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0

   DHCP Enabled. . . . . . . . . . . : No

   Autoconfiguration Enabled . . . . : Yes

Tunnel adapter Local Area Connection* 12:

   Media State . . . . . . . . . . . : Media disconnected

   Connection-specific DNS Suffix  . :

   Description . . . . . . . . . . . : 6TO4 Adapter

   Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0

   DHCP Enabled. . . . . . . . . . . : No

   Autoconfiguration Enabled . . . . : Yes

Tunnel adapter Local Area Connection* 13:

   Media State . . . . . . . . . . . : Media disconnected

   Connection-specific DNS Suffix  . :

   Description . . . . . . . . . . . : 6TO4 Adapter

   Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0

   DHCP Enabled. . . . . . . . . . . : No

   Autoconfiguration Enabled . . . . : Yes

Rebecca,

Did you just re-install Windows recently?

Did you try logging into your wireless router? Plug the ethernet cable into the wireless router and open Internetr Explorer. To log in, put 192.168.1.1 in the address bar and hit enter. It will ask you for your username and password. How to login to your wireless router

Then try using these Recommended Wireless Router Settings in your wireless router.

If you're trying to connect wirelessly, then unplug the ethernet cable and restart your computer. You cannot connect to both wireless and wired at the same time.

Rick