Access to the registry key is denied (ABCPdf)

Perhaps it's a problem between IE9 and ABCPDF.If this error comes by using AddHtml() or AddImageHtml() , I suggest you to change the Rendering Engine from MSHtml to Gecko.

theDoc.HtmlOptions.Engine = EngineType.Gecko;

http://www.websupergoo.com/support.htm

In my case, this solution solved my error.

Who is the CURRENT_USER? Assuming it's an ASP.NET application identity, have you tried loading its user profile?

Open up IIS Manager and navigate to the application pool for your site. In the Advanced Settings dialog, set Load User Profile to True.