raffe,

You said...

I have two laptops one of them i have problem to connect to wifi and the other one works good please help me =(

Make and model fo your computer and operating system is helpful. 32-bit or 64-bit?

What virus program and firewall are you using?

Can you run an ipconfig /all log and post it back here.

Rick

It's dell studio1745 64-bit

Microsoft Windows [Version 6.1.7600]
Copyright (c) 2009 Microsoft Corporation.  All rights reserved.

C:\Users\guitarist>ipconfig/all

Windows IP Configuration

   Host Name . . . . . . . . . . . . : guitarist-PC
   Primary Dns Suffix  . . . . . . . :
   Node Type . . . . . . . . . . . . : Hybrid
   IP Routing Enabled. . . . . . . . : No
   WINS Proxy Enabled. . . . . . . . : No
   DNS Suffix Search List. . . . . . : hsd1.il.comcast.net.

Wireless LAN adapter Wireless Network Connection:

   Media State . . . . . . . . . . . : Media disconnected
   Connection-specific DNS Suffix  . : hsd1.il.comcast.net.
   Description . . . . . . . . . . . : Intel(R) WiFi Link 5100 AGN
   Physical Address. . . . . . . . . : 00-24-D6-4F-B7-F6
   DHCP Enabled. . . . . . . . . . . : Yes
   Autoconfiguration Enabled . . . . : Yes

Ethernet adapter Local Area Connection:

   Connection-specific DNS Suffix  . : hsd1.il.comcast.net.
   Description . . . . . . . . . . . : Realtek RTL8168D/8111D Family PCI-E Gigab
it Ethernet NIC (NDIS 6.20)
   Physical Address. . . . . . . . . : 00-24-E8-EF-7F-01
   DHCP Enabled. . . . . . . . . . . : Yes
   Autoconfiguration Enabled . . . . : Yes
   Link-local IPv6 Address . . . . . : fe80::2c2e:6d8a:9a5f:b64b%11(Preferred)
   IPv4 Address. . . . . . . . . . . : 192.168.1.100(Preferred)
   Subnet Mask . . . . . . . . . . . : 255.255.255.0
   Lease Obtained. . . . . . . . . . : Monday, June 18, 2012 6:09:26 AM
   Lease Expires . . . . . . . . . . : Tuesday, June 19, 2012 6:09:24 AM
   Default Gateway . . . . . . . . . : 192.168.1.1
   DHCP Server . . . . . . . . . . . : 192.168.1.1
   DHCPv6 IAID . . . . . . . . . . . : 234890472
   DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-17-6F-BD-3E-00-24-E8-EF-7F-01

   DNS Servers . . . . . . . . . . . : 75.75.75.75
                                       75.75.76.76
   NetBIOS over Tcpip. . . . . . . . : Enabled

Tunnel adapter isatap.hsd1.il.comcast.net.:

   Media State . . . . . . . . . . . : Media disconnected
   Connection-specific DNS Suffix  . : hsd1.il.comcast.net.
   Description . . . . . . . . . . . : Microsoft ISATAP Adapter
   Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
   DHCP Enabled. . . . . . . . . . . : No
   Autoconfiguration Enabled . . . . : Yes

Tunnel adapter Local Area Connection* 11:

   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : Teredo Tunneling Pseudo-Interface
   Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
   DHCP Enabled. . . . . . . . . . . : No
   Autoconfiguration Enabled . . . . : Yes
   IPv6 Address. . . . . . . . . . . : 2001:0:4137:9e76:24b8:1126:9d31:f674(Pref
erred)
   Link-local IPv6 Address . . . . . : fe80::24b8:1126:9d31:f674%13(Preferred)
   Default Gateway . . . . . . . . . : ::
   NetBIOS over Tcpip. . . . . . . . : Disabled

C:\Users\guitarist>

raffe,

Control Panel\All Control Panel Items\Power Options\Create a Power Plan

Select High performance.

Start, control panel, device manager. Click on Network and then right click on your wireless adapter, left click properties, power management. Uncheck the box, allow computer to turn off this device to save power.

While in the device manager, Have you settings match mine. My Intel WiFi 5100 AGN Connectivity Settings

Rick

thank you for your help but it did not work stil same problem =(

Welcome to Dell Community Technical Forum !

Please try these steps to connect to your wireless network

To view and connect to available wireless networks :

1. Open Connect to a Network by clicking the network icon in the notification area on the bottom right corner of the window.

2. In the list of available wireless networks, click your network name, and then click Connect.

Note : Some networks require a network security key or passphrase. To connect to one of your networks, ask your network administrator or Internet service provider (ISP) for the security key or passphrase.

If you are unable to see any network name, Make sure your wireless switch is on.

To Turn on wireless switch :

Press Fn+F2 key to turn on wireless radio. You can also press Windows logo button + letter “X” to open mobility center to check the status of your wireless card.

If you are still unable to connect, try removing the preferred network using following steps and try reconnecting to wireless network.

To Remove Preferred Network:

Click the start button and click on Control Panel.

In the Control Panel window, select Network and Sharing Center.

Click on Manage wireless networks.

Select your network name you wish to remove, make sure it is highlighted then click Remove.

A window will prompt you to confirm the removal of the network profile you selected to remove.  Click Yes to continue.

Post me back if there is error message which you come across.

Thank you,

Rajaraman_u

Certified Dell Community Professional

raffe,

Try using these Recommended Wireless Router Settings in your wireless router, I use channel 11. I would make a new SSID to make connecting easier.

What is the make and model of your wireless router?

What virus program and firewall are you using?

Rick

Linksys by cisco model WRT120N

I don't know how to check What virus program and firewall i'm using

raffe,

I forgot about the virus program and firewall.

Start, all programs, look and see if you have McAfee, Norton or some other type of virus program installed. Sometimes an expired virus program may cause you not to be able to connect to the internet. I have seen this.

Rick

raffe,

I found THIS LINSYS ARTICLE that may be helpful.

Did you use the Recommended Wireless Router Settings (They suggested using WPA2-PSK(TKIP) Security(Personal) and using channel 11. Make a new SSID to make connecting easier. (I use WPA-PSK(TKIP) Security (Personal). I have wireless devices, like printers, cell phones and other wireless devices and they work well with these settings.

Try reading my article, Installing My Wi-Fi Technology

Download the drivers from Intel's website and save them to the desktop.

Make a system restore point. 

Start, control panel, device manager, network, right click on the Intel® WiFi Link 5100 AGN adapter, left click uninstall. Tell it to also remove the drivers and software.

Restart your computer.

When you log back in, the new hardware wizard will run and you may get adapter not found or not installed properly. Install the drivers saved to your desktop using the instructions I have in the article.

Then try to connect. What happens?

Rick