Modern installers usually have a silent or quient installation switch which allows an unattended install to be performed. Below is a quick guide to unattended application installation:

First try using the /? switch e.g. >setup.exe /? to see if the command line options are detailed.

Next try some of the most common switches:

/s
/silent
/q
/quiet
/s /v/qn
/passive

InstallShield often recognises the /r switch to record an installation and create an answer file (setup.iss). The /f1 switch allows the answer filename and path to be specified as /f1filename (no space) e.g. /r /f1C:\unattend.iss

Some installers have custom install switches e.g. Adobe Reader 8.0 which accepts /sAll or /sPB (progress bar).

Some installers read config files which are in the same directory as the setup file e.g. CyberLink PowerDVD 7.0 which requires silent=1 to be added to custom.ini and EnableLangDlg=N set in setup.ini.

For a more comprehensive explanation of installers and unattended switches follow this link: http://unattended.sourceforge.net/installers.php

When all else fails you can use VBScript to send keystrokes to the application as shown in the example below. Most installers accept ALT-N (%n) for Next, ALT-I (%i)  for Install and ALT-F (%f) for Finish but you can experiment to find the right keys. Ensure you leave a time delay long enough for the actual installation stage so that the final keystroke is not lost.

Set objShell = WScript.CreateObject("WScript.Shell")
objShell.Run "C:\setup.exe"

Wscript.Sleep 1000
objShell.SendKeys "%n"

Wscript.Sleep 1000
objShell.SendKeys "%n"

Wscript.Sleep 1000
objShell.SendKeys "%n"

Wscript.Sleep 1000
objShell.SendKeys "%n"

Wscript.Sleep 1000
objShell.SendKeys "%i"

Wscript.Sleep 30000
objShell.SendKeys "%f"

Wscript.Echo "Complete"