How can I access the server side registry from a COM object called by php?

On the server, I would like to call a dll from php. Using a COM object. This is not a problem until I tried some WPF functionality.

I am getting the following error:

PHP Fatal Error: Exception for 'com_exception' with message 'Source: mscorlib Description: The requested registry access is not allowed. '

Through the ProcMon utility, I found that only 1 access is denied, raised to

HKU \ S-1-5-20 \ Software \ Microsoft \ Wisp \ Pen \ SysEventParameters

This key is used for some "Erasing by Using Pen" . I am not doing anything with this class. It seems to have called initialization or something.

this process is php-cgi.exe call from NT AUTHORITY \ NETWORK SERVICE user. In regedit.exe, I saw that this user has access to the key.

Is it possible to use WPF on the server, right? I think I have to drop the protection somewhere.

Can anyone point me in the right direction?