Trying to get a relative's new computer online. A little awkward as I have to come home to make any inquiries over the net.

Relative's old system was running Windows 2000 on a mere 8GB hard drive. Was acquired second hand and relative has no recovery media and no indication of a recovery partition. While trying to resolve corrupt PFN list error (research indicates might be RAM problems) registry got corrupted. System won't boot in normal or safe mode. Was attached directly to a D-Link cable modem via an Ethernet cable.

I live about four miles away and subscribe to the same ISP (but am using a different brand of cable modem).

Relative's new system is Vista Home Premium SP1 64 bit (quite a step up). Minimal printed setup instructions were included in the box, primarily one of those quick setup sheets that resembles a poster. Quick setup sheet only advised connection of keyboard, mouse, display, speakers and power cord prior to powering up computer and allowing auto configuration to commence. Therefore I didn't connect the Ethernet cable at that time. After some of the auto configuration a screen indicated no network connectivity and offered the option to attempt to detect network again or wait until desktop appeared. At that point I connected the Ethernet cable and clicked the "button" to for the computer to try detecting the network again, but it still failed to connect.

Took the option to wait until the OS was operating to attempt to resolve the networking issue.

Eventually contacted ISP's customer support. Representative reported he was able to communicate with the modem and the NIC in the computer. Despite Vista's connections properties dialog indicating that the IP address and DNS server address was to be automatically assigned, the system is stubbornly refusing to list any addresses for the gateway or the DNS server in the Vista connection status pop-ups or the command prompt's "ipconfig /all" listing. Resetting the modem via the ISP representative's remote control and later disconnecting and reconnecting the modem's power cord did not improve the situation. Disconnection and reconnecting the Ethernet cable at both ends didn't help either. Each of these methods only results in temporary "Identifying Network" message in the connections listing window followed by "Unidentified Network" message.

Thanks in advance for any suggestions and thoughts on the possibility that there is a software or hardware problem with the new computer. Should I send her back to the dealer with the system?

Just out of curiosity. Did you inform to the cable company that this is a new device on the network. Some cable ISPs still require a declaration process when a new device is connected. I had this problem for some time until I bought a router and placed that in between the modems and my machines.

I would press the ISP a little more. Are you getting a link light on the NIC itself? If you are and they can see your card then it should be their problem to fix.

Another thought. Can you connect this box to your network?

In case I neglected to make it clear in the original post, the relative's old Windows 2000 computer had been operating several years connected directly to the cable modem with an ordinary category 5 Ethernet cable. That's the very configuration shown in the ISP's online customer installation articles.

Since the original post the relative took her new computer back to the chain retailer to have them make sure the network adapter was working properly. They reported that it worked at the store, but I'm not sure if they connected it to the store's LAN or directly to a cable modem.

I had the idea I could test her cable modem by temporarily taking my Windows XP computer to her home. As a preliminary trial I bypassed my router/WAP. My computer couldn't connect without both the router and cable modem either. I abandoned that idea while the relative went out of town for a couple of days. Emails were piling up!

The relative then made then appointment with the ISP for in home broadband installation. The ISP's field tech was able to get his notebook to connect properly to the internet, but was unable to get the relative's new computer to properly negotiate a usable connection. The field technician had no better luck with a replacement cable modem. My relative indicated she wasn't going to be charged for the home service call (I'm assuming they will be charging her for the new modem, as she wasn't renting the original one).

The relative was considering an expensive field call from the retailer's technical service team. Lacking any better ideas I took my router to her home and connected it between the modem and new Vista computer. Without any setting changes to the computer's or router's TCP/IP settings the computer was suddenly able to establish a usable connection. She wasn't enthusiastic about the two added devices (router and power pack) and added cabling, but with the option being no internet connection she accepted the necessity of the router. I'll explain the advantages of the router's NAT and SPI functions when she's had more time to adjust to the user interface differences between Windows 2000 and Windows Vista. She promptly started dealing with an almost 400 message Email backlog.

I managed to replace my router with a new 802.11g unit before the sale ended at a prominent chain retailer. It also worked promptly after being connected. Since neither the relative or I are planning to use a wireless connection for the immediate future both routers are set to leave the WAP unused.

So the actual problem is resolved, but I'm still in the dark about why the ISP's recommended hardware configuration failed for both computers. The WAN side of both routers are configured for the same TCP/IP settings the ISP is recommending for computers connected directly to the modem. Since my new router so quickly established a connection without making any arrangements with the ISP I'm doubting the MAC address on the computers was an issue. As an additional note, the labeling on my modem shows different MAC addresses for its HFC and CPE sides.

That is really strange. I agree with you it doesn't sound like Mac registration is the issue. Although your relative isn't incredibly happy with the wiring right now I'm sure the benefits of the router will far outweigh the extra spaghetti. Glad you found the resolution!

Your Windows Vista Firewall would allow the network ID provided by your router since the default 192.168.1.x network is not routable (visible) on the Internet. But your address provided directly by Cable/DSL modem would blocked by the Windows Firewall since it is seen as an immediate security risk. You would have to authorize the addition of this network and you would have limited connectivity until you do.

Don't change it out now. Since you have the router, leave it in place. It is much more secure than a direct connection to the Internet.

There are a few "special" IP address ranges that are not allowed for use on the Internet. The 192.168.1.x range is one of them. This is why it is so much safer to use as a home network address range.

Maybe I've been misunderstanding the abilities of the firewall included with the Windows XP operating system, but I thought it merely blocked incoming packets from IP addresses that the computer hadn't recently set outgoing packets to. I'm not aware of it making any analysis of which IP addresses are in ranges commonly used for WAN or LAN purposes.

Probably not at the root of the problem anyway, as the direct connection to the cable modem attempts weren't successful with the Windows firewall turned off either.