Taking the complexity out of reading a Windows installer Verbose log file
Recently a fellow MSI consultant - Mike Snodgrass of Snodgrass Engineering, (http://snodgrassengineering.com) sent me the “WiLogUtil” the MSI Log utility from the Windows SDK. A great tool in helping to taking the complexity out of reading a very obscure log file. Being a non-Code developer, I rarely take the time to scope out the SDK offerings – so thanks Chris!
I have been dissecting MSI Log files for quite a while, using them to debug if and when my Custom Actions fired and what the results were. (Hint: use a unique name prefix such as “ISI_CustomActionName” to both differentiate and allow you to find your Custom Actions easily).

The Analyze feature offers some good insight into the various client/server States with an excellent MSI Properties snapshot capability.
The selling feature in the MSI Log utility is the button “HTML Log” which will convert the log into color coded sections. The legend is in the top menu – makes evaluation easier if you are new to the MSI Logs.

Link
Here is a link within the MSDN site to the resource http://msdn.microsoft.com/en-us/library/aa372811.aspx – it allows you to reference directly the correct Windows Installer SDK.
There is a nice – but compact topic to reading the Log file available from the button