Why/how are Registry Entries Hidden in Regedit but visible in PowerShell?

Question

I'm working with a new property schema, and have been in the habit of checking the registry when I register or unregister a new version. One of the primary places to check this is HKEY_LOCAL_MACHINE\SOFTWARE\MICROSOFT\WINDOWS\CURRENTVERSION\PROPERTYSYSTEM\PROPERTYSCHEMA.

Interestingly, I occasionally lose access to this registry location in Regedit. I see see this (note the absence of PropertySchema):

I know the schemas are still registered, because I can use the prop.exe tool and propschema SDK sample application to describe them. The properties are available in Windows Explorer and in Search.

Also, I can use PowerShell to list the contents of this hive:

C:\Users\carlton> cd hklm:
HKLM:\>
C:\Users\carlton> cd hklm:
HKLM:\> cd SOFTWARE\MICROSOFT\WINDOWS\CURRENTVERSION\PROPERTYSYSTEM\PROPERTYSCHEMA
HKLM:\SOFTWARE\MICROSOFT\WINDOWS\CURRENTVERSION\PROPERTYSYSTEM\PROPERTYSCHEMA> dir


    Hive: HKEY_LOCAL_MACHINE\SOFTWARE\MICROSOFT\WINDOWS\CURRENTVERSION\PROPERTYSYSTEM\PROPERTYSCHEMA


Name                           Property
----                           --------
0000                           (default)  : C:\Program Files\Internet Explorer\ie9props.propdesc
                               SchemaId   : {D9B5ABA1-5E8A-4902-B6A1-50B3C0311C2E}
                               URI        : ie9props.propdesc
                               CompactURI : 5376bae4b39f43768806afcb6b8ff5464bf9c989d1a819c6e6d99ba1e8ce2512
0001                           (default)  : C:\Program Files\Microsoft Office\Office14\Custom.propdesc
                               SchemaId   : {537AAAB1-1D85-48DC-A99E-16EB8C309FE5}
                               URI        : custom.propdesc
                               CompactURI : 2e3be58e5cbbc0da093956b46a3905f11cf0f5bbf11987a8619e25f7261ee8be
0002                           (default)  : C:\apps\MSOffice\Office14\VisioCustom.propdesc
                               SchemaId   : {18503526-0466-4942-AC6E-41C1D380EABA}
                               URI        : visiocustom.propdesc
...

Anyway, I don't understand how this happens, and whether I should be worried about it. Exporting this key from a colleague's machine and re-importing it can temporarily help, as it will show keys in Regedit that were hidden/missing (even if they weren't on my colleague's machine).

I'm in the Administrators group, running Windows 7 SP1.

Answer 1

The 32bit program data on 64bit systems available in 'Wow6432Node' folder of the registry (in above case 'SOFTWARE\Wow6432Node\MICROSOFT\WINDOWS...'). This is transparent to the applications, hence you can read data from applications but you don't see that in Regedit.

Answer 2

Harry Johnston's intuition was correct. I re-ran regedit from a command line with the path c:\windows\regedit, and I once again see what I expected under HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\PropertySystem\PropertySchema. I could've sworn it wasn't showing it either, but it's working now, apparently.

I confirmed as much by exporting the parent key (PropertySystem) from the 64-bit and 32-bit regedit's and running Beyond Compare. The propdesc files are verily not there in the 32-bit version.

See 32-bit and 64-bit Application Data in the Registry (MSDN)