Installation was not successful The referenced assembly could not be found. ERROR_SXS_ASSEMBLY_MISSING(0x80073701 System Readiness reports no issue. Performing an Upgrade on the server using the 2008 R2 SP1 media returns an error saying that SP1 needs to be installed first. =============================== Checking System Update Readiness. Binary Version 6.1.7601.21645 Package Version 11.0 2011-03-10 14:23 Checking Windows Servicing Packages Checking Package Manifests and Catalogs Checking Package Watchlist Checking Component Watchlist Checking Packages Checking Component Store Summary: Seconds executed: 462 No errors detected =============================== C:\Windows\Logs\CBS\ =============================== 2011-03-10 14:15:59, Error CSI 000002d5@2011/3/10:19:15:59.755 (F) d:\w7rtm\base\wcp\componentstore\csd_locking.cpp(324): Error STATUS_SXS_ASSEMBLY_MISSING originated in function CCSDirectTransaction::LockComponent expression: (null) [gle=0x80004005] 2011-03-10 14:16:00, Error CSI 000002d6 (F) STATUS_SXS_ASSEMBLY_MISSING #631177# from CCSDirectTransaction::OperateEnding at index 0 of 1 operations, disposition 2[gle=0xd015000c] 2011-03-10 14:16:00, Error CSI 000002d7 (F) HRESULT_FROM_WIN32(ERROR_SXS_ASSEMBLY_MISSING) #631062# from Windows::ServicingAPI::CCSITransaction::ICSITransaction_PinDeployment(Flags = 0, a = Microsoft-Windows-CertificateServices-OCSPManagement-Deployment-LanguagePack, Version = 6.1.7600.16385, pA = PROCESSOR_ARCHITECTURE_AMD64 (9), Culture = [l:10{5}]"en-US", VersionScope = 1 nonSxS, PublicKeyToken = {l:8 b:31bf3856ad364e35}, Type neutral, TypeName neutral, PublicKey neutral, cb = (null), s = (null), rid = [126]"Microsoft-Windows-CredentialManagementRole~31bf3856ad364e35~amd64~en-US~6.1.7601.17514.OnlineRevocationServicesManagementTools", rah = (null), manpath = (null), catpath = (null), ed = 0, disp = 0)[gle=0x80073701] 2011-03-10 14:16:00, Info CBS Failed to pin deployment while resolving Update: OnlineRevocationServicesManagementTools from file: (null) [HRESULT = 0x80073701 - ERROR_SXS_ASSEMBLY_MISSING] 2011-03-10 14:16:00, Info CBS Failed to resolve item[0] in Package: Microsoft-Windows-CredentialManagementRole~31bf3856ad364e35~amd64~en-US~6.1.7601.17514, Update: OnlineRevocationServicesManagementTools [HRESULT = 0x80073701 - ERROR_SXS_ASSEMBLY_MISSING] 2011-03-10 14:16:00, Info CBS Failed to resolve execution update. [HRESULT = 0x80073701 - ERROR_SXS_ASSEMBLY_MISSING] 2011-03-10 14:16:00, Error CBS Failed to resolve execution package: Microsoft-Windows-CredentialManagementRole~31bf3856ad364e35~amd64~en-US~6.1.7601.17514 [HRESULT = 0x80073701 - ERROR_SXS_ASSEMBLY_MISSING] and 2011-03-10 14:21:54, Error CBS SPI: (CSPInstall::Install:1583)Failed executing Install task hr=0x80073701 2011-03-10 14:21:54, Info CBS SPI: Ending SP Installation 2011-03-10 14:21:54, Error CBS SPI: (PerformSPInstallation:833)Failed to install SP using UI hr=0x80073701 2011-03-10 14:21:54, Error CBS SPI: (wmain:1105)Failed to perform SP installation hr=0x80073701 2011-03-10 14:21:54, Info CBS SPI: Reporting Failed event

Hi, You might need to perform an in-place upgrade of Windows Server 2008 R2. This will repair all missing/damaged files. Tim Quan

I'm running an upgrade using the 2008 R2 media now. Trying to do an upgrade using the 2008 R2 SP1 media results in an error saying it needs SP1 installed first. Is this simply a wording confusion; calling an upgrade what is actually a repair install?

Delirious - So did the inplace upgrade work for you and/or were you able to complete in the upgrade/repair install? I've got the same issue and I'm about to try the upgrade as soon as I finish the ISO download. I've tried Windows Update and the standalone installer - both ending with the mentioned error.