Last week I noticed high processor usage on my laptop.   (I was using Process Explorer http://technet.microsoft.com/en-us/sysinternals/bb896653.aspx to monitor my system.)  The culprit was an application called TrustedInstaller.exe.   I did some research and found a page on Scott Hanselman’s  blog  that described a similar situation: http://www.hanselman.com/blog/MSMPENGEXETrustedInstallerexeSearchIndexerAndSLSVCEXEAt100CPUOnMyVistaMachines.aspx.   It suggested upgrading to Vista Service Pack 1 to fix the problem.

Ok, I go to upgrade: Control Panel->Security->Check for Updates, and I find no SP1 upgrade.  What is the deal?   After doing some more research, it turns out that one of my optional updates that I had not installed was not so optional.   I needed to upgrade my Conexant HD Audio driver.  Here is the link where I found that information:  http://support.microsoft.com/kb/948343.   I installed the Conexant HD Audio driver, and still no sign of SP1 when I check for updates.  I then install all of the remaining optional Windows Vista updates (not the Windows Ultimate Extras and not the Windows Vista Ultimate Language Packs) and restart my laptop.  I check for updates again and FINALLY the SP1 upgrade appears.  An hour later, Vista Service Pack 1 is successfully installed on my PC.  

I then get into my Visual Studio 2008 IDE and notice that I cannot debug my application.  I get the following error:  Unable to start debugging on the web server. Unable to connect to the web server. Verify that the web server is running and that incoming HTTP requests are not blocked by a firewall.

I do some more research and find that I need to start the World Wide Web Publishing service.  For some reason, it is not started.  That fixed the debugging problem in the Visual Studio 2008 IDE.   Here is the link where I found that information:  http://forums.asp.net/p/1235884/2302214.aspx#2302214

To date, I have not had any other issues with Vista SP1, and it did seem to fix the problem with the TrustedInstaller.exe application consuming enormous amounts of CPU time. 

John