< Windows
Renaming a Windows computer from a remote console: (if in a domain and you have the domain admin password of course)
netdom.exe renamecomputer <oldcomputername> /newname:<newcomputername> /userd:<yourdomain>\administrator /passwordd:<yourpassword> /usero:<yourdomain>\administrator /passwordo:<yourpassword> /force >> c:\renamelog.txt
sure, logging to file is optional.