The last week of 2011 was a busy one in our team with the release of critical update MS 11-100.

During this week, I've been working on a customer's incident dealing with the inability to install the IIS Web Server role on a W2K8 computer. The CBS installation log (C:\Windows\Logs\CBS) was showing the following :

2011-12-27 11:36:44, Info                  CSI    0000003a Begin executing advanced installer phase 34 (0x00000022) index 59 (0x0000003b) (sequence 91)
    Old component: (null)
    New component: Microsoft-Windows-IIS-W3SVC, Version = 6.0.6001.18000, pA = PROCESSOR_ARCHITECTURE_INTEL (0), Culture neutral, VersionScope = 1 nonSxS, PublicKeyToken = {l:8 b:31bf3856ad364e35}, Type neutral, TypeName neutral, PublicKey neutral
    Install mode: install
    Installer ID: {d82eedee-854e-4f9a-b458-ae1bc62a0e6b}
    Installer name: [16]"LodCtr Installer"

2011-12-27 11:36:44, Error                 CSI    00000001@2011/12/27:10:36:44.770 (F) Logged @2011/12/27:10:36:44.759 : [ml:182{91},l:180{90}]"RegQueryValue_ServiceFirstCounter("SYSTEM\CurrentControlSet\Services","W3SVC") fails (2,0)"
[gle=0x80004005]
2011-12-27 11:36:44, Error                 CSI    00000002@2011/12/27:10:36:44.770 (F) CMIADAPTER: Inner Error Message from AI HRESULT = HRESULT_FROM_WIN32(1010)
[46]"Cl\u00e9 du Registre de configuration non valide" <= English translation : "The configuration registry key is invalid"

The above CBS log output is similar to the one described in this post : http://forums.iis.net/t/1170019.aspx. Unfortunately, we tried to apply the resolution from this post but could not succeed in installing the Web Server Role. The issue was finally resolved after recreating the Perfmon counters registry keys using "lodctr /r". In fact, the "The configuration registry key is invalid" cryptic message mainly means that Perfmon registry keys are "corrupted" and need to be rebuilt. There are similar problems & resolutions on the web : http://social.msdn.microsoft.com/forums/en-US/winformssetup/thread/09a26089-6849-4dd6-a590-714a49dda609/). Note that before rebuilding the performance counters, it is recommended to backup current Perfmon counters registry keys using lodctr /s:"perfbkp.txt". After rebuilding the counters, the IIS role could be installed without any problem.

I hope this blog will help any folk having this problem…

Emmanuel