1. Exception – Failed to create the configuration database. An exception of type System.Security.Cryptography.CryptographicException was thrown. Additional exception information: The data is invalid.
Resolution – This has two steps
Step 1: Make sure that the “Network Service” account has full access to the “14” directory under %commonprogramfiles\Microsoft Shared\Web Server Extensions.
Step 2: Delete the registry key located under “SOFTWARE\Microsoft\Shared Tools\Web Server Extensions\14.0\Secure\FarmAdmin” Registry key and then run the SharePoint 2010 Products Configuration Wizard.
It is likely that this registry key is required to be cleared each time you run the wizard after an unsuccessful attempt :)
2. Exception - Failed to register SharePoint Services. An exception of type System.Runtime.InteropServices.COMException was thrown. Additional exception information: Could not access the Search service configuration database.
I followed these steps and the configuration finished successfully.
1. On the Start menu, click Run. In the Open box, type regedit and then click OK.
2. In the Registry Editor, navigate to the following subkey, and then delete it:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Shared Tools\Web Server Extensions\12.0\WSS\Services\Microsoft.SharePoint.Search.Administration.SPSearchService3.
Run the SharePoint Products and Technologies Configuration Wizard again.