RegOpenKeyEx Returning Error Code 87 aka INVALID_PARAMETER

Revision 4
Hi All,
I have written a code to recursively delete the registry keys from HKLM and HKCR. While deleting the HKLM keys pose no problem but HKCR keys exit with the error code 87 i.e., INVALID_PARAMETER.
Any idea on what's going on?

My Code Snippet::
hKey = Predefined Root Key, lpszSub = SubKey To be Deleted
Works fine on: Vista and Win7 but throws Error on XP x86

static BOOL K7RT_RcrsvRegDel( HKEY hKey, LPTSTR lpszSub )
{
	BOOL	bRet = TRUE ;
	LONG	lRet ;
	DWORD	dwSize = MAX_PATH ;
	TCHAR	szName[MAX_PATH] ;
	TCHAR	szFullKey[MAX_PATH * 2] ;
	HKEY	hKeySub = NULL ;
	HRESULT hr = NULL ;
		
	do{
		lRet = RegOpenKeyEx( hKey, lpszSub, 0, KEY_ALL_ACCESS |KEY_WOW64_32KEY , &hKeySub ) ;
		printf("RegOpenKey:: %S :: lRet = %ld\n", lpszSub, lRet) ;
		if( lRet != ERROR_SUCCESS )
		{
			if( lRet == ERROR_FILE_NOT_FOUND )
			{
				bRet = FALSE ;
				break ;
			}
			else
			{
				bRet = FALSE ;
				break ;
			}
		}

		while( ERROR_NO_MORE_ITEMS != (lRet = RegEnumKeyEx(hKeySub, 0, szName, &dwSize, NULL, NULL, NULL, NULL)) )
		{
			hr = StringCchPrintf( szFullKey, MAX_PATH*2, TEXT("%s\\\\%s\0"), lpszSub, szName ) ;
			if( hr != S_OK )
			{
				bRet = FALSE ;
				break ;
			}
			szName[0] = '\0' ;
			dwSize = MAX_PATH ;

			bRet = K7RT_RcrsvRegDel( hKey, szFullKey ) ;
			if( bRet == FALSE )
				break ;
		}
		
		if( hKeySub != NULL )
		{
			RegCloseKey(hKeySub) ;
			hKeySub = NULL ;
		}

		lRet = RegDeleteKey( hKey, lpszSub ) ;
		printf("RegDelKey:: %S :: lRet = %ld\n", lpszSub, lRet) ;
		if( lRet == ERROR_SUCCESS )
		{
			bRet = TRUE ;
			break ;
		}
	}while(0) ;
	return bRet ;
}