SQL Server installation fails when it tries to modify registry

Hi all,

I have a clustered Windows 2008 R2 with two nodes. When I try to install SQL Server 2012 in cluster mode, it encounters an error regarding to "unauthorized access". I checked the setup log and saw the following lines:

Slp: Creating cluster network name 'LeilaSQL'.
Slp: Creating cluster resource 'SQL Network Name (LeilaSQL)' of type 'Network Name' in group 'SQL Server (I5)'
Slp: Node 'LeilaONLINEDB1' is already a possible owner node of resource 'SQL Network Name (LeilaSQL)'
Slp: Removing possible owner node 'LeilaONLINEDB2' from resource 'SQL Network Name (LeilaSQL)'
Slp: Setting the LanMan properties registry key NoRemapPipe value to enable remote operations against the network name for machine LeilaONLINEDB1.
Slp: Sco: Attempting to create base registry key HKEY_LOCAL_MACHINE, machine LeilaONLINEDB1
Slp: Sco: Attempting to open registry subkey SYSTEM\CurrentControlSet\Services\lanmanserver\parameters
Slp:   LanMan properties registry key opened.
Slp: Sco: Attempting to get registry value NoRemapPipes
Slp:   Setting the LanMan properties registry key NoRemapPipe value to 'winreg, svcctl, eventlog'.
Slp: Sco: Attempting to set value NoRemapPipes
Slp: Prompting user if they want to retry this action due to the following failure:
Slp: ----------------------------------------
Slp: The following is an exception stack listing the exceptions in outermost to innermost order
Slp: Inner exceptions are being indented
Slp: 
Slp: Exception type: Microsoft.SqlServer.Configuration.Sco.ScoException
Slp:     Message: 
Slp:         Attempted to perform an unauthorized operation.
Slp:     HResult : 0x84bb0001
Slp:         FacilityCode : 1211 (4bb)
Slp:         ErrorCode : 1 (0001)
Slp:     Data: 
Slp:       WatsonData = parameters@NoRemapPipes
Slp:       DisableRetry = true
Slp:     Inner exception type: System.UnauthorizedAccessException
Slp:         Message: 
Slp:                 Attempted to perform an unauthorized operation.
Slp:         HResult : 0x80070005
Slp:         Stack: 
Slp:                 at Microsoft.SqlServer.Configuration.Sco.InternalRegistryKey.SetValueMultiString(String name, Object value)
Slp:                 at Microsoft.SqlServer.Configuration.Sco.InternalRegistryKey.SetValue(String name, Object value, RegistryValueKind valueKind)

Any help would be greatly appreciated.

Leila