How Smoke Alarms Work. Smoke alarms, which are also called smoke detectors, work by constantly checking the air for traces of the gasses and smoke particles produced by a fire. There are two types of smoke alarms-ionization alarms and photoelectric alarms.moke alarms, which are also called smoke detectors, work by constantly checking the air for traces of the gasses and smoke particles produced by a fire.
Exporting items from OST to PST is the best way to create backup of OST file. If you are connected with Exchange server, you can easily do this via manual method. In other case, you should try some third party tool.
Restoring the database from a known good copy is the easier option if a recent backup is available. By default, Win2K and NT 4.0's DHCP services automatically create a backup copy of the DHCP database once per hour in the server's \%systemroot%\system32\dhcp\backup\jet\new folder.