Windows 2000 log on option

You can log in locally, if there is an Administrator account in it, as it will authenitcate with itself, than the DC, then to ...

If there is a problem with the network, then you will need these options...

1.If you can logon with local Admin account verify the network settings and also you can try to reauthenticate your computer in domain. For that remove from Server Manager the workstation name from list. Log on workstation with local with local admin rights and in network properties set as member of workgroup. Reboot computer. Log on again as local admin and set as member of domain and set the option . Give the information about name and password of the Domain Admin. Reboot computer.
2.If you can't logon localy, use other workstation/server logon with Domain admin account use from menu change domain to <\\WorkstationName> and you will see all local accounts for this workstation. Here you change password of the local admin or add an account. Use these new settings and return to step 1.
About recover the information if previous steps don't work:
You can put the HDD in other computer as slave and copy all your data.

I think I'm reading your question differently than the others who have answered.

1. In Win98, you can actually put anything you want in the "Domain" box. If Windows doesn't recognize the name as a valid domain, it will acutally create a workgroup with whatever name you entered.
2. In NT, if you are referring to multiple entries in the "Domain" pull-down menu on the log-on screen, these are all domains that have had Trust relationships created with your domain. This is the only way in which different domain names can be added to this window.
3. In Win2K, there is one of 2 possibilities as to why you don't see a "Domain" window. One, your computer has not been joined to a domain; or two, you don't have the log-on screen fully expanded. If you don't see an Options button on the log-on screen, the answer is one. If you see an Options button and either it is greyed out or the arrows are pointing to the right, the answer is two. If the button is greyed out, then your administrator has applied a security policy to stop you from viewing the domain name. If the button is not greyed out, all you need to do is click once to expand the screen.

As to the possibility of you messing up the domain setting, you need domain admin privileges to do so. If you manage to change the settings using the local administrator account (all you would be able to do is remove the machine from the domain), it would take someone with domain admin privileges to rejoin you to the domain.