Hi Chad,
Thank you for your interest in Essential PDF.
It is possible to use your PDFDocument object in a Windows Service.
Could you please make sure that your project has a
"licenses.licx" file with the following entry for syncfusion components in your project.
"Syncfusion.Core.Licensing.LicensedComponent, Syncfusion.Core"
http://www.syncfusion.com/Support/user/uploads/license_4dd5ae62.zipYou can just include this file in your project that uses PDF.
Also, can you please try the following trouble shooting tips in the attached file,
http://www.syncfusion.com/Support/user/uploads/Troubleshooting tips_944ecc7c.zipKindly let me know if you have any other queries.
Regards,
Sarath