Hi Shrenik,
Thank you for your interest in Syncfusion products.
Yes, it is possible to use Essential PDF in a Windows Service to generate the PDF documents.
If you already have license file please include it in the application or please use the below file in your project and set it as an embedded resource:
http://files.syncfusion.com/samples/pdf.windows/licenses_55824.zipPlease use the below assemblies with all in same version in your application.
Syncfusion.Compression.Base.dll
Syncfusion.Core.dll
Syncfusion.Pdf.Base.dll
Please try to use in a Windows Service and let us know if you face any issues in that.
Best Regards,
Bhuvana