Blank screen after changing admin paswd

if this is what happened to you then you will need to roll up sleeves to fix it.
tell them they will be down until monday in case more goes wrong. but you will get home early tonight with system up. how are backups? wonder if you can restore folder with original permissions??? good time to review after this is all over...
you can fix this...
the answer is simple and maybe easy if you have room on hd for 'rescue' win2k installation. you will need to have mass storage drivers for that box available. is scsi or ide boot disk?
i would consider money to call microsoft for help. they will hold hand tight and not let you make it worse. they won't be busy on friday and always worth the money in the learning experience...they will be available Monday for followup questions at no charge. you will be happy.
they might have easiest/fastest way and you can review what to do when admin leaves next time etc etc...
----anyway, here is some comfort maybe---
fronm mskb 155315, maybe some comfort.
NOTE: You do not receive any warning that removing the Everyone group removes all users, including administrators, and you are not warned that some system-wide functions may no longer work.

CAUSE
Removing the Everyone group and selecting the Replace Permissions On Subdirectories check box removes all users, including administrators, and prevents anyone from accessing the partition.
RESOLUTION
To resolve this issue and allow users to log on after this problem has occurred, use any of the following methods:
Method 1
Set up Windows NT on another partition or hard disk in the computer, using the following steps:

Set up Windows NT on another partition or hard disk.
Log on to the new installation of Windows NT as an administrator.
Take ownership of the original partition.
You should be able to gain access to the data files on the original partition.

Method 2
Reformat the partition and reinstall Windows NT using the following steps:

Reformat the hard disk partition on which Windows NT is installed.
Reinstall Windows NT, and then restore any data files from a backup.
Method 3
Use File Manager to change the permissions. To do so, follow these steps:

Log on to the computer using an account with administrator privileges.
Press CTRL+ALT+DELETE, and then click Task Manager.
On the File menu, click New Task(Run).
In the Open box, type "winfile" (without quotation marks), and then press ENTER.
Click the boot drive, and then click Permissions on the Security menu.
Grant the Everyone group Change permissions.
Close File Manager, and then restart your computer.

MORE INFORMATION
To prevent the Everyone group from having explicit rights to the partition without preventing access by any user, use the following steps:

Grant the user who is currently logged on, or a group that contains the user currently logged on, proper access to the partition. For example, the Administrators group should be granted Full Control permissions.
Grant the System group Full Rights.
Remove the Everyone group.
Click the Replace Permissions On Subdirectories check box so that it is selected.
Click OK.
NOTE: Granting the System and Owner groups full access to the partition after removing the Everyone group does not allow the default user ID, or administrator, permissions to log on and access files even though it is considered an owner. To grant permissions to the Administrators group, you must explicitly add the Administrators group.

The user attempting to log on must have sufficient permissions granted before logging on. The minimum permissions necessary to log on (assuming the System group has full control of the volume root and all system directories and files) are:

%SystemRoot%: Everyone - READ

%SystemRoot%\System32: Everyone - READ/EXECUTE

%SystemRoot%\System32\Repl\Import\Scripts: Everyone - READ/EXECUTE
(if users have logon scripts)
Depending on your environment, additional permissions may be necessary.