I have a Dell laptop that I was trying to connect to my home network. This laptop had been a little feisty lately, but seems to have worked fine the last few times I booted it up. I was having absolutely no success in getting the laptop to communicate with the rest of my Windows XP/2000 network, so I figured that removing the laptop from the domain it was associated with and using my home workgroup name could make things work better, so I did. Upon rebooting the laptop, I find that the username and/or password of the laptop's only user are invalid. For reasons beyond my control, I need to regain access to this account. The only scenario I've come up with to fix it is to boot the laptop on a copy of live Ubuntu, Mount the hard drive, grab the registry files, and switch the laptop back from workgroup mode to domain mode.

I've had problems before, and the community here was amazing, so I figured I'd try again. Thanks in advance,
Sterkenburg

Logging into a Domain and logging in locally are not the same, as you've discovered. You can't add the client machine back into a Domain to which it's not connected. So, If you have a local account, use that to login locally. If you don't have a local account, take the machine back to work and have one of your Admins add the client back into the Domain.

Life's more painless for the brainless.

There is one single account on the laptop, that that is the one that is (was?) linked to the domain. The account always worked when the laptop had no internet connection, so the laptop doesn't have to communicate with any domain servers or anything, just Windows won't accept the username and password. If there was any way to simply undo what we did, miaculously log into that account and switch the setting right back, just the radio button on the "Computer Name" tab in the My Computer properties, I think it would work exactly the way it used to. But of course, miracles don't happen to laptops. So there isn't really a way to trick Windows into thinking it is changed back, ie. through the registry? That was the basis to my entire theory with the linux.

Again, thanks.
Sterkenburg

The Domain "account" is actually a Domain Profile. There is a default Local Administrator account on every Windows machine. That account cannot be deleted, so it still exists.

The Domain login profile worked before when disconnected from the Domain because the login was cached. Windows won't accept those login credentials because you removed the Domain login option when you put the machine in a Workgroup. Therefore, you need to login with the Default Administrator account and password.

Life's more painless for the brainless.

Jennifer said it Exactly. You will have to have one of your admins at your company readd the computer to the domain. They will know exactly what happened. I've delt with that from our Sales people a lot. Sometimes they did it on their own but most of the time they were unaware because their home router software made the change. It asked them but it did not explain the end result.

It's a simple fix for your admins, don't worry, all your data is still on the computer.

I understand that the change is entirely reversible--with access to the domain, of course. I had no idea the profile only worked because the information was cached, that explains a lot. Thanks for your help!