Can't install Hyper-V client on Windows 8 Pro

Question

Resolved.
I use dataram ramdrive, all temps & history stored there, changed back temporarily to a temp folder on C: - the install completed.
So, something should have been left in the temp location for windows update to do something with, after the actual install finishes, fails and reverts  - that's where it seems to fall over.
I select the items to install, reboot, start windows update, reboot, fail, rollback
Hyper-V Requirements:      VM Monitor Mode Extensions: Yes
                           Virtualization Enabled In Firmware: Yes
                           Second Level Address Translation: Yes
                           Data Execution Prevention Available: Yes
As far as I can see, my machine should support it
log name: setup
source: servicing
event id: 11
Update Microsoft-Hyper-V of package Microsoft-Hyper-V-ClientEdition-Package failed to be turned on. Status: 0x800f0922
It seems "failed to be turned on. Status: 0x800f0922" is an error thrown up for quite a few different things not installing, each with it's own resolution, none are specific to hyper-v.

Answer 1

I'm having exactly the same problem, with the same missing file reported in CBS.log.
event-log:
<Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event">
<System>
<Provider Name="Microsoft-Windows-Servicing" Guid="{BD12F3B8-FC40-4A61-A307-B7A013A069C1}" />
<EventID>11</EventID>
<Version>0</Version>
<Level>0</Level>
<Task>1</Task>
<Opcode>0</Opcode>
<Keywords>0x8000000000000000</Keywords>
<TimeCreated SystemTime="2013-02-10T12:46:09.954774500Z" />
<EventRecordID>1532</EventRecordID>
<Correlation />
<Execution ProcessID="1132" ThreadID="1196" />
<Channel>Setup</Channel>
<Computer>Sorcerer</Computer>
<Security UserID="S-1-5-18" />
</System>
<UserData>
<CbsUpdateChangeState xmlns="http://manifests.microsoft.com/win/2004/08/windows/setup_provider">
<UpdateName>Microsoft-Hyper-V</UpdateName>
<PackageIdentifier>Microsoft-Hyper-V-ClientEdition-Package</PackageIdentifier>
<ErrorCode>0x800f0922</ErrorCode>
<Client>Windows Optional Component Manager</Client>
</CbsUpdateChangeState>
</UserData>
</Event>
CBS.log:
 Completion status: S_OK
2013-02-10 15:31:24, Info                  CSI    0000005d Begin executing advanced installer phase 38 (0x00000026) index 82 (0x0000000000000052) (sequence 121)
    Old component: [l:0]""
    New component: [ml:330{165},l:328{164}]"Microsoft-Hyper-V-Drivers-Hypervisor-Bcd, Culture=neutral, Version=6.2.9200.16384, PublicKeyToken=31bf3856ad364e35, ProcessorArchitecture=amd64, versionScope=NonSxS"
    Install mode: install
    Installer ID: {3eca0b00-79bb-42b9-8421-a26a5cbb37e4}
    Installer name: [41]"Boot Configuration CSI Advanced installer"
2013-02-10 15:31:24, Info                  CSI    0000005e Performing 1 operations; 1 are not lock/unlock and follow:
  (0)  LockComponentPath (10): flags: 0 comp: {l:16 b:eb80f84d9b07ce01380000007004bc04} pathid: {l:16 b:eb80f84d9b07ce01390000007004bc04} path: [l:238{119}]"\SystemRoot\WinSxS\amd64_microsoft-hyper-v-drivers-hypervisor-bcd_31bf3856ad364e35_6.2.9200.16384_none_6e8b90a1724c0f3c" pid: 470 starttime: 130049802597993719 (0x01ce079b3ef68cf7)
2013-02-10 15:31:24, Error                 CSI    0000005f@2013/2/10:14:31:24.977 (F) base\boot\bcd\tools\bcdedit\ai\bcdeditai.cpp(230): Error HRESULT_FROM_WIN32(ERROR_FILE_NOT_FOUND) originated in function Windows::WCP::BcdEdit::BasicInstaller::Install expression: InnerStatus
[gle=0x80004005]
2013-02-10 15:31:24, Info                  CBS    Added C:\WINDOWS\Logs\CBS\CBS.log to WER report.
however both “DISM /Online /Cleanup-Image /RestoreHealth” and
“sfc /SCANNOW” did not solve the problem for me, any other suggestions?