This is the installation tool that can be used on version 4.4 and lower Samsung OfficeServ 7100, OfficeServ 7200 and OfficeServ 7400 VoIP/Digital phone systems.
Installation_Tool_V1.43b_(2009.11.04)

At any Samsung phone with a display – do not lift handset
Press Transfer 800
Display says enter passcode – enter 4321 (If you get a pass code error start over and use Transfer 200 and the pass code 1234 instead)
Press 1 to enable programming
press speaker
dial 505 to enter the time and date program
display show WMMDDYYHHMM
W = [...]

An unsupervised conference call allows two outside lines to be connected together in a trunk to trunk conference (no internal telephones).

Step 1: While engaged in a conversation press the Conference Button or CONF Softkey (On your display).
Step 2: Select an outside line or dial 9 and make the second call.
Step 3: When the second call [...]

This is the latest patch (version 2.75b) for the Samsung OfficeServ 500 phone system OfficeServ Manaager (OSM). Download, unzip and run setup.exe.
www.askemergent.com/downloads/OSM500P(080528)_V3.75b.zip

Download Samsung OfficeServ 7100 version 4.04 here.

The feature code for Do Not Disturb on the Samsung iDCS 28D and IDCS18D (or any Samsung phone for that matter) is 40 + 1 for on or 0 for off.
Enable Do Not Disturb

Leave your handset in the handset cradle
dial 40 on the keypad
Press 1 or the softkey under ON

Disable Do Not Disturb

Leave your handset [...]

EDIT:The latest version IT can be found here: http://www.askemergent.com/installation-tool-130a
This is the installation tool that can be used on version 4.14 and lower Samsung OfficeServ 7100, OfficeServ 7200 and OfficeServ 7400 VoIP/Digital phone systems.
www.askemergent.com/downloads/IS_tool_v114.zip

The first thing you should do when you enter programming mode is locate your cursor. Look on the top line, first character and you should see a small underscore, this is your cursor. To move the cursor around you use the left and right soft keys (the three keys directly underneath your display). [...]

These are the button codes used when programming the buttons on a Samsung OfficeServ 7100, 7200, 7400, iDCS 100 or iDCS 500 phone system. Some of the buttons will require an extender after the code (signified by the X) , for example when programming a station button (DS) you will need to add the [...]

This will reset a subscriber’s (user) password in Samsung SVMi-2e, SVMi-4e, SVMi-8e, SVMi-16e and SVMi-20e voice mail systems. 
 
Press the voice mail button.
Press the * key.
When you hear your greeting dial # 0 0 0 0.
Enter the password 0 0 0 0.
Press 2 for subscriber admin.
Enter the number of the phone/mailbox (ex. 203) and then the pound key.
If you entered [...]