If the domain controller that is the Schema Master FSMO role holder is temporarily unavailable, DO NOT seize the Schema Master role.
If you are going to seize the Schema Master, you must permanently disconnect the current Schema Master from the network.
If you seize the Schema Master role, the boot drive on the original Schema Master must be completely reformatted and the operating system must be cleanly installed, if you intend to return this computer to the network.
NOTE: The Boot Partition contains the system files (%SystemRoot%\System32). The System Partition is the partition that contains the startup files, NTDetect.com, NTLDR, Boot.ini, and possibly Ntbootdd.sys.