If you type msiexec /? it pops a window with this text in it:

Windows (R) Installer. V 3.01.4001.5512

msiexec /Option <Required Parameter> [Optional Parameter]

Install Options
	</package | /i> <Product.msi>
		Installs or configures a product
	/a <Product.msi>
		Administrative install - Installs a product on the network
	/j<u|m> <Product.msi> [/t <Transform List>] [/g <Language ID>]
		Advertises a product - m to all users, u to current user
	</uninstall | /x> <Product.msi | ProductCode>
		Uninstalls the product
Display Options
	/quiet
		Quiet mode, no user interaction
	/passive
		Unattended mode - progress bar only
	/q[n|b|r|f]
		Sets user interface level
		n - No UI
		b - Basic UI
		r - Reduced UI
		f - Full UI (default)
	/help
		Help information
Restart Options
	/norestart
		Do not restart after the installation is complete
	/promptrestart
		Prompts the user for restart if necessary
	/forcerestart
		Always restart the computer after installation
Logging Options
	/l[i|w|e|a|r|u|c|m|o|p|v|x|+|!|*] <LogFile>
		i - Status messages
		w - Nonfatal warnings
		e - All error messages
		a - Start up of actions
		r - Action-specific records
		u - User requests
		c - Initial UI parameters
		m - Out-of-memory or fatal exit information
		o - Out-of-disk-space messages
		p - Terminal properties
		v - Verbose output
		x - Extra debugging information
		+ - Append to existing log file
		! - Flush each line to the log
		* - Log all information, except for v and x options
	/log <LogFile>
		Equivalent of /l* <LogFile>
Update Options
	/update <Update1.msp>[;Update2.msp]
		Applies update(s)
	/uninstall <PatchCodeGuid>[;Update2.msp] /package <Product.msi | ProductCode>
		Remove update(s) for a product
Repair Options
	/f[p|e|c|m|s|o|d|a|u|v] <Product.msi | ProductCode>
		Repairs a product
		p - only if file is missing
		o - if file is missing or an older version is installed (default)
		e - if file is missing or an equal or older version is installed
		d - if file is missing or a different version is installed
		c - if file is missing or checksum does not match the calculated value
		a - forces all files to be reinstalled
		u - all required user-specific registry entries (default)
		m - all required computer-specific registry entries (default)
		s - all existing shortcuts (default)
		v - runs from source and recaches local package
Setting Public Properties
	[PROPERTY=PropertyValue]

Consult the Windows (R) Installer SDK for additional documentation on the
command line syntax.

Copyright (c) Microsoft Corporation. All rights reserved.
Portions of this software are based in part on the work of the
Independent JPEG Group.

2008/12/6 Martin v. Löwis <report@bugs.python.org>:
>
> Martin v. Löwis <martin@v.loewis.de> added the comment:
>
>> In order to install python silently, run
>>
>> msiexec python-2.5.2.msi /quiet
>
> I'm puzzled. According to all msiexec documentation I could find,
> there is no /quiet option to msiexec (plus you also need to specify
> /i, according to the docs). I'll have to find out what this does
> first.
>
> _______________________________________
> Python tracker <report@bugs.python.org>
> <http://bugs.python.org/issue4567>
> _______________________________________
>