When you deploy a PowerBuilder Web Forms application to IIS 7 or later, the application is deployed to a PowerBuilder-specific application pool named PBDotnet4AppPool.
PBDotnet4AppPool uses the default application pool identity, which is NetworkService on IIS 7, and ApplicationPoolIdentity on IIS 7.5. However several Web Forms application features, including the creation of permanent user accounts, SSL authentication, and DataWindow Print and SaveAs commands, do not work with the default IIS 7.5 application pool identity. To enable these features, you must change the PBDotnet4AppPool application pool identiity to NetworkService.