Windows 7: Internet Connection

Just upgraded to Windows 7 32bit. Have a linksys modem and linksys wireless router, with the main computer with Windows 7 connected via ethernet to router, and laptop and iPod touch able to surf via wireless router.

Here's my problem....The computer can be OFF, and all my devices (iPod touch, laptop) can get on the internet and everything works fine on those devices. I turn on the computer that the router is attached to, and a few seconds after the Windows 7 welcome screen appears, I can no longer surf the internet on my devices (nor the computer). It's almost as if Windows 7 is blocking my router. Like I said, the computer can be OFF and my internet works fine. Turn Windows 7 on, and everything quits. I have to unhook and bypass the router and just have my cable modem go straight to my computer in order to get on the internet.

What do I need to do to Windows 7 to allow me to use the router?

Interesting. I suspect your router is simply broken, and the presence of an ethernet connection is giving it a heart-attack.

A few simple tests:

1) Does the laptop have the same debilitating effect when it's hooked up to the router via a cat5 cable? (Keep the Windows 7 machine completely off and disconnected during this test so there's definitely no chance it's interfering.)

2) As a separate test, boot the Windows 7 box but stop at the POST screen (press 'pause' on the keyboard as soon as you see white-on-black text during the boot). Does it once again knock out all internet connectivity? This is not as conclusive as (1), but I'm curious what would happen.

No, the router can not be broken. It worked fine yesterday with XP, and even works fine when the computer is off, before Win 7 boots up.

1) Laptop works fine when hooked up with ethernet cable from the router.

2) At the pause, it does not knock out internet connectivity. I can surf on my other devices no problem. That is, until Win 7 boots up.

The more I play with this, the more I think it's the modem and not the router. I can watch the "receive" light on the modem and it's blinking away doing its thing, and then the Win 7 starup screen comes on and BAM, the light quits blinking. Thus, no longer can surf. It's like Win 7 is booting up, checking in with the modem, not liking what it "sees", and shutting it down. Very aggravating.

I'm getting a similar problem to this.

Modem is a Motorola SBG900.

Basically when I turn on the computer with Win 7 after about 5 minutes the modem cycles through a complete restart.

This never occured when XP Pro was installed and it doesnt happen with my mac or Hp Laptop. So the problem is decidedly with Windows 7, or a software issue with the modem, but thats up to date.

Comp Specs are:
Windows 7 64x
Intel i7 920 oc'd to 3.0
msi x58 pro-e
3x1 GB 10666 DDR ocz ram
creative soundblaster xfi blah its not part of the problem
two 500gb hdd in raid 0
two ati HD Radeon 4850 in crossfire

What should I kill and who should i sacrifice to make my modem happy with Windows 7?

Thanks in Advance

Even more interesting

3) Once internet connectivity has been lost, does each machine still have a seemingly valid IP lease (IPCONFIG /ALL)? Can each machine ping the router's inner interface - 192.168.0.1 or whatever?

4) At the point where you've booted into Windows 7 and all internet connectivity has been lost, can the machines on the LAN still ping each other by their "local" IP addresses? In other words - PING 192.168.03 - or whatever the address range may be.

5) As a separate test, if you boot the Windows 7 box into safe mode (as opposed to [safe mode + net]), does the ensuing lack of internet connectivity still happen?

6) You're not running a DHCP server of some sort on that Windows 7 box, are you? ICS, sygate... anything which would attempt to "share" the internet connection by setting itself up as a DHCP server to give out IP leases - anything like that? To put it differently, one way for a computer to suddenly mess things up by booting is to run a DHCP server that pumps out bogus IP leases. Even then, I wouldn't expect the results to be quite so immediate, but it's a possibility.

H2SO4,

I appreciate your help in this matter. Here are my results:

3) Once internet connectivity has been lost, each machine does still have a seemingly valid IP address. And yes, each machine can ping the router's inner interface.

4) And yes, the machines on the LAN can still ping each other by their "local" IP addresses.

5) Don't mean to sound like a noob, but don't know how to boot Win 7 in safe mode.

6) No, I'm not running a DHCP server on Win 7 machine. All I did was do a clean install of Win 7 and encountered these problems.

Any other suggestions?

I appreciate your help.

Press F8 as soon as the POST section of the boot sequence is over and you see the first sign of "Windows". You should then get a menu that allows you to pick "safe mode", "safe mode with networking", plus several other options. I'd be interested to know what effect "safe mode" and "safe + net" has on the situation.

The situation is very curious, though you no doubt prefer to refer to it as "frustrating" right now. Just thinking out loud, I'm relatively confident that there is something wrong with your router or the modem, although it's not possible to be sure which one is at fault based on the currently available info.

Yes, the presence of the Windows 7 machine obviously makes a difference to the outcome, but there should be no way that a healthy router/modem is knocked out by the sudden arrival of a client machine sporting any given OS. In other words, you referred to Windows 7 "shutting down the modem", and my point is that it can't do that - the modem/router is "shutting down" in response to something which shouldn't be able to knock it out.

In addition to the safe mode tests...

7) Once the Windows 7 machine boots (in normal mode) and the problem develops, can you log on to the router via its web (HTTP) management interface? Can you see whether it still has a valid "external" (real) IP address lease from the ISP? Can any of the client machines ping that external IP?

8) Does shutting down the Windows 7 box restore connectivity for the other clients? You may as well just yank its network cable for this test.

9) When you get into the state where connectivity is lost, can you call the ISP and ask them to tell you what they see from their end - do they perceive your modem as connected, or is it gone from their network? I'm not suggesting that the ISP is at fault in any way, but it would be useful to know what the symptom looks like from their perspective.

10) What sort of "modem" is it exactly? Cable/coax? DSL? Old-fashioned phone?

No problem at all. I like trying to understand out-of-the-ordinary symptoms, and this one qualifies

As I mentioned, my guess is that some relatively innocuous network activity by the Windows 7 box - LLTD perhaps - is causing the modem/router to have a spasm, and technically that's a flaw in the modem/router, even though for all practical purposes it looks like the Windows 7 box is causing the problem.

I agree with H2S04. The Windows 7 machine cannot be causing the other devices to lose internet connectivity so there is definitely something wrong with either the modem or your router.

An easy way to figure out if it's your modem:

1. Unplug the router from the modem
2. Unplug the power supply from the modem
3. Plug your Windows 7 machine directly to the modem
4. Plug power to the modem back in (wait at least 15 seconds)

If you have internet connectivity while plugging in directly to the modem then the problem is going to be with your router.

I know you say that it was working fine yesterday with Windows XP, but I tell people that when it comes to electronics it doesn't care what it was doing a year ago, a month ago, a week ago, a day ago or even a minute ago. If they're going to fail they're going to fail no matter what.

Try that and post back with your results.