no access on second computer

I have two computers that have internet access. Up until a few days ago I had no trouble connecting to the internet with either one of them. Now one computer can connect with no problem until I turn on the second computer then I lose the connection. Some time I can turn off that second computer and I regain access other times I have to turn off the modem and back on to get access again. If I just turn on the second computer I lose the connection and restarting the modem does not help. Any ideas!

Hello,

Is this a wired or wireless connection? If its wired check your cables and be sure they are not bent or crushed.

What information I could come up with about the system
PC that connects...
Windows 7 Home Premium (x64) Service Pack 1 (build 7601)
Intel Core i7 DB65AL mother board
4MB memory
2.60 gigahertz Intel Pentium G620 Dual Core
2nd PC that has the problem...
Windows XP (SP3)
AMD Athlon 1.9GHz
2MB memory (i think)
Modem/Router....
AT&T 2Wire Gateway Wired connection

My PS3 and Ipad connect ok wireless

I lose the connection when the 2nd computer has finished booting and loading the OS

I lose the connection just as the 2nd computer boots the operating system.

Sounds like you have an IP conflict. Can you post your IP configuration from both machines?
Go to start >run
Type cmd
then issue command ipconfig/all
post results.

Thanks for the reply CarlosH
I booted the second PC and I did get the modem icon in the system tray to indicate it had
a connection and it did load a page although it was slow but then the modem lost the connection. I also unistalled Zone Alarm free firewall and am now using the windows FW once again.
Here is the info from the computer that connects...

Microsoft Windows [Version 6.1.7601]
Copyright © 2009 Microsoft Corporation. All rights reserved.

C:\Users\Rick> ipconfig/all

Windows IP Configuration

Host Name . . . . . . . . . . . . : Rick-PC
Primary Dns Suffix . . . . . . . :
Node Type . . . . . . . . . . . . : Hybrid
IP Routing Enabled. . . . . . . . : No
WINS Proxy Enabled. . . . . . . . : No
DNS Suffix Search List. . . . . . : gateway.2wire.net

Ethernet adapter Local Area Connection:

Connection-specific DNS Suffix . : gateway.2wire.net
Description . . . . . . . . . . . : Intel® 82579V Gigabit Network Connection
Physical Address. . . . . . . . . : 38-60-77-E0-2C-00
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
Link-local IPv6 Address . . . . . : fe80::a063:de91:7fef:bb5b%11(Preferred)
IPv4 Address. . . . . . . . . . . : 192.168.1.67(Preferred)
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Lease Obtained. . . . . . . . . . : Tuesday, July 31, 2012 20:22:13
Lease Expires . . . . . . . . . . : Wednesday, August 01, 2012 20:22:13
Default Gateway . . . . . . . . . : 192.168.1.254
DHCP Server . . . . . . . . . . . : 192.168.1.254
DHCPv6 IAID . . . . . . . . . . . : 238575735
DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-17-5A-B1-91-38-60-77-E0-2C-00

DNS Servers . . . . . . . . . . . : 192.168.1.254
NetBIOS over Tcpip. . . . . . . . : Enabled

Tunnel adapter isatap.gateway.2wire.net:

Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . : gateway.2wire.net
Description . . . . . . . . . . . : Microsoft ISATAP Adapter
Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes

Tunnel adapter Teredo Tunneling Pseudo-Interface:

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. . . . . . . . . . . : 2001:0:9d38:953c:4c:2ae7:9c83:4250(Preferred)
Link-local IPv6 Address . . . . . : fe80::4c:2ae7:9c83:4250%13(Preferred)
Default Gateway . . . . . . . . . : ::
NetBIOS over Tcpip. . . . . . . . : Disabled

C:\Users\Rick>

Here is the info on the PC that causes the disconnect....
Microsoft Windows XP [Version 5.1.2600]
© Copyright 1985-2001 Microsoft Corp.

C:\Documents and Settings\Rick.USA-1>ipconfig/all

Windows IP Configuration

Host Name . . . . . . . . . . . . : SECOND
Primary Dns Suffix . . . . . . . :
Node Type . . . . . . . . . . . . : Broadcast
IP Routing Enabled. . . . . . . . : No
WINS Proxy Enabled. . . . . . . . : No
DNS Suffix Search List. . . . . . : gateway.2wire.net

Ethernet adapter Local Area Connection 2:

Connection-specific DNS Suffix . : gateway.2wire.net
Description . . . . . . . . . . . : SiS190 100/10 Ethernet Device
Physical Address. . . . . . . . . : 00-25-11-F6-7B-BC
Dhcp Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
IP Address. . . . . . . . . . . . : 192.168.1.69
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Default Gateway . . . . . . . . . : 192.168.1.254
DHCP Server . . . . . . . . . . . : 192.168.1.254
DNS Servers . . . . . . . . . . . : 192.168.1.254
Lease Obtained. . . . . . . . . . : Tuesday, July 31, 2012 4:25:39 PM
Lease Expires . . . . . . . . . . : Wednesday, August 01, 2012 4:25:39 PM

C:\Documents and Settings\Rick.USA-1>

Have you tried :
1.Changing cables and using/swapping LAN port from the modem/router?
2.Reinstalling or updating the network driver of the problematic PC?
3.Disabling other protections softwares temporarily for testing purposes?
4.Resetting the router to factory defaults?
5.Disabling/Clone MAC filtering on router settings if available?
6.Called ISP for insurance that its not from their device is the issue?
A static IP may help but make sure you have followed the steps first as enumerated.

Download SecurityCheck.exe from Here

. Run SecurityCheck and follow the instruction from inside the code box.
. When the scan is finished, a notepad will automatically open as check.txt
Please copy and paste the contents here on your next reply.

Download Speccy and then install the program. To post and publish a snapshot of your PC.
. In the Menu bar, click File -> Publish Snapshot
. Click Yes > then Copy to Clipboard
. On your next reply, right-click on a empty space and click Paste on reply box then click [b]Post[/b

Thanks jhayz
That list of "did you try" is beyond my abilities except for number 1,3&4.
I did an ipconfig /release then ipconfig /renew
The PC DID connect but was very slow. The modems lights did go out except for the power and ethernet
lights but then all the lights came back on and stayed on. The internet was still very slow. The status
on the system tray icon for the connection showed very low packet numbers but they increased to about
10k and 15k (approximate). The PC running win 7 had good speed.

here is the link for the speccy program. The securitycheck program did not go past the "Performing system
health check" screen. I let it sit there for about 4 minutes and gave up on it. Does it take longer then that?

http://speccy.piriform.com/results/lQ8m2VUPI76sX7sBKpFqsWH

Try pinging the 2wire modem/gateway from each computer when the internet disconnects.

To do this, open up command prompt (same window you did the ipconfig from) and enter:

ping 192.168.1.254

What reply did you get? When the internet isn't working try running these commands (without the quotes). PC 1 is the computer that works correctly and PC2 is the second computer that knocks your internet out:

**IMPORTANT: MAKE SURE YOU RUN THESE COMMANDS IN THE LISTED ORDER. PC2's COMMAND MUST BE RUN BEFORE PC1**

PC 2: "ipconfig /release"

PC 1: "ipconfig /release" and then do the command "ipconfig /renew"

Did the internet start back working?

If PC1 isn't on, is PC2 able to access the internet?

Are there any P2P (ex: bit torrent, file sharing, etc.) programs installed on the second computer? Have you confirmed that the 2nd computer is virus/malware free?

The securitycheck program did not go past the "Performing system
health check" screen. I let it sit there for about 4 minutes and gave up on it. Does it take longer then that?

Try letting it run for 20-30 minutes. If it still hangs, then end it and post back.

OK NpaMA thanks for the reply
I ran the ping on both computers and they came up as follows....
PC1
Microsoft Windows [Version 6.1.7601]
Copyright © 2009 Microsoft Corporation. All rights reserved.

C:\Users\Rick>ping 192.168.1.254

Pinging 192.168.1.254 with 32 bytes of data:
Reply from 192.168.1.254: bytes=32 time=2ms TTL=255
Reply from 192.168.1.254: bytes=32 time=3ms TTL=255
Reply from 192.168.1.254: bytes=32 time=3ms TTL=255
Reply from 192.168.1.254: bytes=32 time=2ms TTL=255

Ping statistics for 192.168.1.254:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 2ms, Maximum = 3ms, Average = 2ms

C:\Users\Rick>
PC2
C:\>ping 192.168.1.254

Pinging 192.168.1.254 with 32 bytes of data:

Reply from 192.168.1.254: bytes=32 time=6ms TTL=255
Reply from 192.168.1.254: bytes=32 time=3ms TTL=255
Reply from 192.168.1.254: bytes=32 time=1ms TTL=255
Reply from 192.168.1.254: bytes=32 time=1ms TTL=255

Ping statistics for 192.168.1.254:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 1ms, Maximum = 6ms, Average = 2ms

C:\>
I have not ran the second phase with the ipconfig because I have not lost the connection on PC2.
All of the lights are on the modem. Browsing is a little slow but not unbearable.
I think what ever happened is not happening any more, at least for now ;)
I guess I can say this has been solved! (?)
Thanks for the help.