What folder are installation logs in?

Question

If an installer stores a log of the installation process, where would I find that log?

If there is an installer that does not log the installation process, how can I make it do so?

Answer 1

Windows installer logs are usually kept in the temp folder, you can get to this by going to run or an explorer bar and type the location as %temp%.

The default folder for this is:

C:\Users\<username>\AppData\Local\Temp

From This MS Support page:

To enable Windows Installer logging yourself, open the registry with Regedit.exe and create the following path and keys:

HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows\Installer

Reg_SZ: Logging

Value: voicewarmupx

The letters in the value field can be in any order. Each letter turns on a different logging mode. Each letter's actual function is as follows for MSI version 1.1:

v - Verbose output

o - Out-of-disk-space messages

i - Status messages

c - Initial UI parameters

e - All error messages

w - Non-fatal warnings

a - Start up of actions

r - Action-specific records

m - Out-of-memory or fatal exit information

u - User requests

p - Terminal properties

+ -Append to existing file

! - Flush each line to the log

x - Extra debugging information. The "x" flag is available only on Windows Server 2003 and later operating systems, and on the MSI redistributable version 3.0, and on later versions of the MSI redistributable.

"" - Wildcard, log all information except for the v and the x option. To include the v and the x option, specify "/lvx".

Note This should be used only for troubleshooting purposes and should not be left on because it will have adverse effects on system performance and disk space. Each time you use the Add/Remove Programs tool in Control Panel, a new Msi*.log file is created.

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Please note that the above is just for MSI files or setups that take advantage of the Windows Installer. Some others will also create log files either in the temp folder, their application directory or the root of the hard drive. There is no one answer fits all.

Answer 2

You can also have the installer write an installation log wherever you like, as needed, without modifying the registry. Run the installer msiexec from the command line with the /L option. For example,

msiexec /i C:\Users\myusername\Downloads\somepackage.msi /L*v install.txt

This will run the install script and write all logging info (verbose) to the file install.txt

The options for the /L flag are:

i : Logs status messages.
w : Logs nonfatal warnings.
e : Logs all error messages.
a : Logs startup of actions.
r : Logs action-specific records.
u : Logs user requests.
c : Logs initial user interface parameters.
m : Logs out-of-memory.
p : Logs terminal properties.
v : Logs verbose output. To use v, specify /L*v.
+ : Appends to existing file.
! : Flushes each line to the log.
* : Logs all information except for the v option. This is a wildcard. 

Source: http://www.microsoft.com/resources/documentation/windows/xp/all/proddocs/en-us/msiexec.mspx

Although the Microsoft support page references Windows XP, I have confirmed that this works for Windows 7.