No disk emac admin psswrd

If you know the current administrator password, you can change it by going to System Preferences: Accounts.
If you've lost the password, you need Disk 1 of the OS install disk set. Start up the computer and put the disk in the optical drive. Restart the computer and hold down the option key immediately after the chime until a disk icon appears on the display. Wait a few seconds more until the optical disk icon appears. Click on this, then on the arrow to boot up from the install disk.
When the OS installer appears, go to the Reset Password... item in the Apple menu and follow the directions there. (Select the administrator account from the pull-down menu.) If your install disk is not specifically for an eMac, or is made for an eMac with a different graphics chip, the display quality may be poor, but you should still be able to pick out what you need to see from the Password applet.

I could suggest you search for this under "Apple password reset" since I've written the solution several times in the last month, but for you, I'll do it again:
You need to find Disk 1 of the operating system install disk set. The install disk set doesn't need to be the one that came with the computer, so long as it is OS 10.2 to OS 10.5 (PPC). However, some install disks are not compatible with the resolution setting of the graphics chip in some eMacs, so you may have difficulty reading the display.
The reset procedure is as follows: Turn on the eMac, open the optical (CD or DVD) drive and place Disk 1 in it, then close the drive. Restart the eMac. As soon as the startup chime sounds, immediately hold down the option key and continue to hold it until a disk icon appears on the screen. Wait until the optical disk icon also shows up. Click on the optical disk icon, then click the arrow button. This will boot up the computer to the install disk.
When the computer boots up to the install program, DO NOT DO ANYTHING IN THE INSTALL PROGRAM. Look in the Apple menu for the Reset password... item. You should see a selector menu for the account(s) on the computer. Select the administrator account and enter the new password (it can be left blank if you know nobody else will ever mess with your computer). Confirm the password, then quit and restart without holding down any keys.
The computer should restart normally and you can log in to the administrator account with the new password. So long as you remember the new password, you can change it at any time using the "Accounts" pane in System Preferences.

You should format the internal hard disk and install a clean and fresh version of Mac-OS anyways and create a new user-account. If there is no install-disc included, try calling Apple, tell them your eMac's serial number (All eMac's have their serial numbers printed inside the disc drive door), and ask them if they have any replacement install discs for your model of eMac. Check out the Apple eMac support page or the Apple eMac support forum for more informations.

Insert your Mac OS disk and attempt a restart with the C key held down. It may be that your eMac isn't recognizing it's hardrive...
You can launch disk utilties off the menu of the OS disk and try to remount your hardrive on your emac...
See if this gets it back.

In OS X, if you're the administrative (or only) user, you can reset the admin/user password using the OS X installation disk #1. Put the disk in the CD drive & restart the eMac while holding the "C" key down (Restart is also on the Apple menu, top-left corner of your screen). When the Installer opens, click "Utilities" then Restart. When the Installer asks you what language, pick one (maybe English?) 8¬), click continue (arrow) then Utilities again & choose "Reset Password"; the system will guide you through the steps. Once you've reset the user password, restart the eMac, then you can log in using the new password. You'll probably want to reset your "Keychain" password to match your new login password – otherwise it'll ask for your password every time it needs one for a program. "Keychain Access" is in the 'Utilities' folder, which is inside the 'Applications' folder.

—> Important: if the old Users Home Folder was encrypted ("FileVault" protected), you'll need the old user's password, or the eMac's Master password to access the files in the Home Folder – otherwise, the Home folder's files will be lost. As a new user, you'll have your own Home Folder & access to all application programs.

Well i don't know of a fix for the issue u have, but i do have a tip and you might be able to fix the issue you have this way as well. But if you plan on transfering files from one mac to another esp. if one is either an older mac or a portable. you would always want to make one or the other a target disk instead of two stand alone mac's.
Why, because your eMac's older and the data transfer might be failing or can't process the data fast enough to get broken down to bits to be put back on the other end thru the cat5 line. But to transfer files of over 1 GB i would recommend you start the iBook in target disk mode. But since your eMac is the one with some issues put the eMac as the target.
To connect two mac using TDM (Target Disk Mode) you will need to get either a 6-pin IEEE to 6-pin IEEE firewire 800 cable, a 6-pin IEEE to 9-pin IEEE firewire 800 cable, or a 9-pin IEEE to 9-pin IEEE (if your eMac has a 9-pin port) firewire 800 cable.
Then you connect the cable to one of the eMac's 6 or 9 pin ports and the other end to one of the iBooks firewire 800 ports. (the iBook has both the 6 pin and the 9 pin. 800 ports) To start up as the target disk you press and hold T immediately after pressing the power on button. once you see the firewire symbol bounce around the screen you can let go. Now its like connecting to a external hard drive.

IF YOU HAVE A DESKTOP OR NOW SOMEONE WHO DOES ,,PUT WINDOWS ON A FLASH DRIVE OR SD CARD AND USE IT TO INSTALL ON YOUR LAPTOP

Hi Sorry to hear you are having troubles,You will need a firewire 400 cableOK, first thing you must do is reboot the eMac in TARGET mode, this means it will be recognized as an external disk. To get the eMac in TARGET mode, you must be sure the eMac is turned OFF and has a functioning keyboard connected.Power on the eMac and very very rapidly press the ( T ) key on the keyboard, be sure the caps lock button is not pressed. If all goes well, you will see the firewire logo appear larger than life on the screen.( If you are unable to get into TARGET mode, it is highly probable that the mother board of the internal hard drive is damaged and preventing the eMac from entering TARGET mode, sorry, that's the end of the line..)Once you enter TARGET mode on the eMac, connect the firewire cable to your G4 PowerBook, you can do this either while it is running or when it is off and then turn it on.
You should see the volume of your eMac internal hard drive appear on the PowerBook desktop...sometimes you need to open Disk Utilities and repair or mount the drive manually.If this all works well, copy the required files directly to your PowerBook...After that, power off both machines, disconnect them and reboot the eMac using a CD or DVD to reformat and reinstall a new system.

Yes you need to start off the install disk, star off the install disk and it will come up to the installer window, depending on the version of OS X the menus will be different. Installer for 10.1-103 and Utilities for 10.4-10.5, select the Reset Password function and you will see a picture of your hard drive, select it and a list of users will appear and you can then reset their passwords.

Assign manually the IP address for the Mac and see the difference