# unable to contact your DHCP server problem



## chilakilez

Hi there,
i've been having this annoying issue with my wireless connection, every now and then it gets disconnected and stays under "Limited Connectivity", i try to reset the IP and get the "unable to contact your DHCP server" problem, and i cannot do any of the ipconfig tasks due to the same error. The main problem is that i cannot have internet again until i restart the laptop, and even if i turn it off and back again, then it says "Windows Cannot find any Networks", or "try switching your wireless mode on", even though it's on and there are about 8 differenet wireless connections in here. 
I know it's my laptop but is the wireless card damaged or something?. 

I have a Toshiba Satellite A100 / SP3
with a
Intel(R) PRO/Wireless 3945ABG Network Connection
and im connected wireless to a WEP.
Drivers are updated and no configurations problems appear under device manager.
Thanks in advance for any help.


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## pccare_himanshu

Some steps which i Know

STEP 1:
***********

Do a power cycle ( Shutdown the computer, unplug the cable from the cable or the 
DSL modem from the back of the tower and also unplug the cable from the DSL or 
cable modem and power off the cable or the DSL modem and restablish the setup after 
2 minutes and power on ) .

STEP 2:
***********
Check the Network Properties for any Network Bridge

How *to* remove the Network bridge :
*********************************************
1. Click on Start and go *to* the Control Panel (start-->settings-->control panel if 
they have it set *to* windows classic)

2. Click on Network and Internet Connections (network connections if they have 
already switched away from category view)

3. Click on Network Connections (you will not use this step if they have already 
switched away from category view)

4. Look out for the things available ( Ask the customer *to* read the names that are 
present )

5. If they have a network bridge, right click on it and choose delete.

More often then not, if they had a network bridge, this will solve the *DHCP* server 
error problem

STEP 3:
*********
You can try resetting TCP/IP with the netsh command or try the netsh dump (commonly 
called by me the netBS commands)

Reset TCP/IP in Windows *XP*
****************************************

1. Click on Start and go *to* Run

2. In the run box type "cmd" or "command"

3. At the command prompt type in "netsh int ip reset reset.txt" and hit enter

You'll see the cursor go down a line for a second or two and then it will go back 
*to* the command prompt.

How *to* do do netsh dump:
*******************************
Netsh dump

This is another IP fix at that I consider sub-par. It sure doesn't fix the reg keys 
and that's what matters some times.

1. click on start and go *to* run

2. type in the run box "cmd" or "command" and click OK

3. At the command prompt type in "netsh dump" and hit enter

A bunch of stuff is going *to* flash across the screen and you will end up back at 
the command prompt.

4. Exit out of the command prompt and reboot.

STEP 4:
*********
Another option would be trying *to* reinstall the NIC or possibly changing the link 
speed, however it is seldom that either of these work.

Reinstalling the NIC :
************************
1. Go *to* the Device Manager

2. click on the plus sign *to* the left of Network Adapters

3. Highlight the NIC and hit delete on the keyboard. It will ask you if you're sure 
you want *to* uninstall it. Click on yes.

4. Reboot

When the system reboots, in the system tray you will see a little bubble window pop 
up saying new hardware found. A little later it should say that the new hardware 
was installed and ready *to* use.

Changing the link speed of the NIC :
******************************************

1. Open up the Device Manager

2. Find the NIC underneath Network Adapters

3. Double click on it

4. Click on the Advanced Tab

5. In the properties list highlight Media Type and change the value on the left *to* 
10mbps Half Duplex or 10 half.

STEP 5:
***********
If the computer is connected *to* the internet by means of a wireless netadaptor, we 
can try connecting the computer *to* the router or the modem by means of a wire. If 
the computer connects *to* the internet by means of the wired connection, then we can 
understand that the problem is with the configuration of the wireless adaptor ( 
Sometimes the wireless netadaptor may have a problem ).

STEP 6:
**********
Put the computer on a partial clean boot and check whether any 3party service is 
causing the problem. Uninstall any 3rdparty firewall ( If present ).

STEP 7:
***********

1) Start >> run >> services.msc >> open" *DHCP* client " >>go *to* "Dependencies" and 
check for the following items.

AFD Networking Support environment
Net BIOS over TCP/IP
TCP/IP Protocol Driver

If you have anything other than this, *DHCP* has been modified by some unidentified 
source. ( Make sure that the *DHCP* client is set *to* automatic and if it is stopped 
make it restart the service ).

2) Navigate *to* HKey_Local_Machine\System\CurrentControlSet\Services\*DHCP* and edit 
the "DependOnService" on the right side.

3) Also Navigate *to* HKey_Local_Machine\System\CurrentControlSet\Services and delete 
winsock and winsock 2.

4) Restart the computer.

5) Reinstall TCP/IP.

How *to* reinstall TCP/IP
***************************
Install TCP/IP :
*****************
i ) Right-click the network connection, and then click Properties.

ii )Click Internet protocol TCP/IP and click Install.

iii )Click Protocol, and then click Add.

iv )Click Have Disk.

v )Type C:\Windows\inf , and then click OK.

vi )On the list of available protocols, click Internet Protocol (TCP/IP), and then 
click OK.

vii )Restart the computer.

NOTE : If you are working with a SP2 installation please dont delete the winsock 
keys from the registry. Use "netsh winsock reset" ( without quotes ) in the command 
prompt *to* reset winsock.

6) Now check the Ip address and also try *to* release and renew it. The error wont 
come 90%.

STEP 8:
**********
We can also try *to* restore the system back *to* an earlier time ( when it was working 
fine ) by doing a system restore.

The best option if none of those work would be *to* try USB if it is available. If 
the customer feels it is the modem then tell them they can swap the cable modem at 
the local office, but if they are still *unable**to* receive an IP address they might 
want *to* consider taking their computer *to* the shop, or troubleshoot the system 
themselves. The reason I say this....we are not responsible for their system.

STEP 9:
**********

If the computer is infected by a lot of spyware none of these steps will work ( 
Sometimes the computer will connect *to* the internet after STEP 3, but it will fail 
*to* work after a couple of restarts. I have faced this kind of situation on one 
call). If this is the case we can do a clean install of 
windows *Xp*.


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## chilakilez

thanks a lot, will try them when it happens and will post back


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## TerryNet

Most of those above steps are going to be a waste of your time, so pick and choose which ones seem relevant to your issue.

When I see "Windows Cannot find any Networks", or "try switching your wireless mode on" the first thing I think of is that you are using an integrated wireless adapter and it is switched off. Have you checked for that when you get either of those messages?

I understand that on Toshibas the switch is low on the front of the laptop, and the LED to indicate status is Red for on. There may also be a software switch (utility).


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## chilakilez

Whenever i turn the switch off, and turn it back on again, then it's when it appears "Windows Cannot find any Networks" if i don't turn it off it remains connected to the network under "Limited Connectivity". 
And indeed, there is a Toshiba utility, same results whenever i turn it off and on.
Somehow there is something that works just restarting the laptop.


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## TerryNet

What operating system?


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## JohnWill

Download and run this Xirrus Wi-Fi Inspector, paste a screen shot of the main screen here.

To post a screen shot of the active window, hold the _*Alt*_ key and press the *PrtScn* key. Open the Windows PAINT application and _*Paste*_ the screen shot. You can then use PAINT to trim to suit, and save it as a JPG format file. To upload it to the forum, open the full reply window and use the _*Manage Attachments*_ button to upload it here.


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## chilakilez

it's Windows Vista Home Premium / SP2 and will do post the screenshot asap, thanks guys


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## TerryNet

> Drivers are updated ...


You have the latest wireless driver from Toshiba's web site, right? Intel warns that sometimes the motherboard or PC manufacturer makes changes to their drivers to make them work in the particular system.


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