PowerShell error for installation SQL Server 2012 RTM Developer on Windows 7 X64

Question

I had a lot of grief with upgrading from 2008 R2 and PowerShell. Created a thread but doesn't seem to be promising to solve it, so de-installed, and now I am installing from scratch 2012 .

And PowerShell again. I don't see any problem with that on Windows level

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Windows PowerShell Copyright (C) 2009 Microsoft Corporation. All rights reserved.

PowerTab version 0.99.6.0 PowerShell TabExpansion Library Host: ConsoleHost PowerTab Enabled: True PS U:> get-executionpolicy RemoteSigned PS U:>

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But installation

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The following error has occurred:

Error while enabling Windows feature : MicrosoftWindowsPowerShell, Error Code : -2146498548 , Please try enabling Windows feature : MicrosoftWindowsPowerShell from Windows management tools and then run setup again. For more information on how to enable Windows features , see http://go.microsoft.com/fwlink/?linkid=227143

For help, click: http://go.microsoft.com/fwlink?LinkID=20476&ProdName=Microsoft%20SQL%20Server&EvtSrc=setup.rll&EvtID=50000&ProdVer=11.0.2100.60&EvtType=0x681D636F%25401428%25401

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Detail.txt

(01) 2012-04-13 12:11:18 Slp: Running Action: Install_PowerShell2_Cpu64_Action (01) 2012-04-13 12:11:18 Slp: Checkpoint: PREINSTALL_POWERSHELL2_CPU64_ACTION (01) 2012-04-13 12:11:18 Slp: Enabling OS feature :MicrosoftWindowsPowerShell, Dism Command: Dism /Online /Enable-Feature /FeatureName:MicrosoftWindowsPowerShell /NoRestart /Quiet /LogPath:"C:\Program Files\Microsoft SQL Server\110\Setup Bootstrap\Log\20120413_115145\MicrosoftWindowsPowerShell.log" (01) 2012-04-13 12:11:18 Slp: Running: Dism /Online /Enable-Feature /FeatureName:MicrosoftWindowsPowerShell /NoRestart /Quiet /LogPath:"C:\Program Files\Microsoft SQL Server\110\Setup Bootstrap\Log\20120413_115145\MicrosoftWindowsPowerShell.log" (06) 2012-04-13 12:11:33 Slp: (06) 2012-04-13 12:11:33 Slp: Error: 0x800f080c (06) 2012-04-13 12:11:33 Slp: (06) 2012-04-13 12:11:33 Slp: Feature name MicrosoftWindowsPowerShell is unknown. (06) 2012-04-13 12:11:33 Slp: A Windows feature name was not recognized. (06) 2012-04-13 12:11:33 Slp: Use the /Get-Features option to find the name of the feature in the image and try the command again. (01) 2012-04-13 12:11:33 Slp: Process returned -2146498548 (01) 2012-04-13 12:11:33 Slp: Failed to enable OS feature :MicrosoftWindowsPowerShell, result: -2146498548 (01) 2012-04-13 12:11:33 Slp: Watson Bucket 1

Original Parameter Values

(01) 2012-04-13 12:11:33 Slp: Parameter 0 : SQL Server 2012@RTM@

(01) 2012-04-13 12:11:33 Slp: Parameter 3 : Microsoft.SqlServer.Configuration.SetupExtension.OSFeatureEnableFailureException@1428@1

(01) 2012-04-13 12:11:33 Slp: Parameter 4 : Microsoft.SqlServer.Configuration.SetupExtension.OSFeatureEnableFailureException@1428@1

(01) 2012-04-13 12:11:33 Slp: Parameter 5 : Install_PowerShell2

Answer 1

It turned out SQL installer despite Windows 7 still checks certain entries in registry for PowerShell existence.
in my case value "install" under HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\PowerShell\1 was non-existent for some reason.

The installer is far from smart, as it expects REG_DWORD "install" under HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\PowerShell\1 with value 1 and if missing, tries unsuccessfully re-install PowerShell on Windows 7.