JSI Tip 1016. Conversion to NTFS causes unknown/invalid account/password on administrative share.

If you you receive:

Incorrect password or unknown username for:\\<Computer>\c$

remove/add the computer from the domain:

1. Run Srvmgr.

2. Select the problem computer and press DELETE. Press Yes

3. Re-add the computer.

You can do this in batch by using NETDOM.