98 Won't boot in normal mode after changing TCP/IP settings

[dhmmjoph]

I was recently given a computer running some legacy server software which allows for the control of LEGO RCX robots with attached webcams over the internet. The machine is running Windows 98. I set up the computer a few days ago only to find that it wouldn't connect to my local network. Upon further inspection, this was due to the computer attempting to assign itself a local IP outside the range acceptable in my network (i.e. the computer wanted to give itself a local IP of 10.104.0.x; my LAN needs an IP in the range 192.168.0.x). This was fixed by opening the control panel, clicking "Network", selecting "TCP/IP" in the "Configuration" tab and clicking "Properties", selecting the "IP address" tab, and changing the selected option from "Specify an IP address" to "Obtain an IP address automatically". After clicking OK I was alerted that a reboot was required, so I clicked "reboot". The computer hasn't been able to be able to boot normally since. If I press the power button, the Dell splash screen appears, then it says "Alert! The cover was previously removed" (not really relevant, but included for completeness), then the Windows 98 splash screen appears, then the screen goes black, but the computer isn't off (the fan still runs and the lights on the front of the case are still lit). If I press the power button when it's in this state, the Win98 splash screen reappears with the overlaid text "Windows is shutting down" and the computer appears to shut down as normal. If I hold down ctrl during boot I can select and boot into safe mode, command prompt only mode, logged mode, and others.

I have tried booting into safe mode and changing the TCP/IP settings back to "Specify an IP address" but with a valid local IP, and this did nothing to solve my problem.

Feel free to ask for clarification; it's reasonably late at night as I write this and some of it may not make sense.

Your help is much appreciated.

[jumper]

If scanregw.exe has been running automatically at startup, you should have a registry backup from each of the last five days. Boot to DOS and "scanreg /restore" a backup from before things went wrong.

If no registry backup is available, change the IP address back to an *invalid* value.

I suspect the black screen is caused by a (LEGO server) app that runs at startup. Without a network connection, it aborts to the desktop. With a valid connection, it waits for a remote (robot) app to talk to it. The black screen is probably a background for displaying webcam feeds on top of.

Pressing the power button is causing Windows to shutdown normally. Instead of pressing the power button, you can try Ctrl+Alt+Del to bring up the task list--kill apps until you get a desktop (or have to shutdown the system).

Once you get to the desktop (by safe mode or other method), run msconfig.exe and use the startup tab to disable extraneous (LEGO) apps from running automatically at boot. Then it should be safe to reconnect to the network.

[dhmmjoph]

Thanks for you help but it turns out the issue was caused by my switching to an LCD monitor. Plugging in a CRT display solved the problem without a reboot.