Windows Setup Guide
How to make PDF Engineer the default PDF app on Windows
Set PDF Engineer as the app Windows uses when you double-click a PDF, so drawings, supplier packets, and review files open directly in your mechanical redline workflow.
Short answer
Assign the .pdf file type to PDF Engineer in Windows Settings
The most reliable path is Settings > Apps > Default apps. Search for the .pdf file type, then choose PDF Engineer as the app Windows should use for PDF documents.
You can also start from a PDF file in File Explorer. Right-click the file, choose Open with, select PDF Engineer, and choose Always so Windows remembers the choice.
Recommended method
Set PDF Engineer as the default from Windows Settings
Use this method when you want a clean system-level association for all local PDF files. It matches Microsoft's documented Default apps workflow for assigning apps by file type.
Install PDF Engineer
Install PDF Engineer first, then open it once. Windows needs to know the app is available before it can appear as an option for PDF file associations.
Open Default apps in Windows Settings
Select Start, open Settings, then go to Apps > Default apps. This is the Windows control area for choosing which apps open each file type.
Search for the PDF file type
In the Default apps search box, type .pdf. Choose the PDF file type result when it appears.
Choose PDF Engineer
Select the app currently assigned to .pdf files, choose PDF Engineer from the list, then confirm the change.
Test a local PDF
Double-click a PDF file from File Explorer. If the association is set correctly, the document should open in PDF Engineer.
File Explorer method
Set the default app from a PDF file
This route is useful when you are already looking at a PDF in File Explorer or when PDF Engineer does not show up immediately in the Settings search results.
Step 1
Right-click a PDF file
In File Explorer, find any local PDF drawing, manual, quote, or review packet, then right-click the file.
Step 2
Open the app picker
Choose Open with. If PDF Engineer is not visible in the first list, choose another app from the dialog.
Step 3
Select PDF Engineer
Pick PDF Engineer as the app you want to use for this file type.
Step 4
Choose Always
Choose Always instead of Just once. On Windows 10, this may appear as an option to always use the selected app for PDF files, followed by OK.
Troubleshooting
If Windows does not open PDFs in PDF Engineer yet
Most default-app issues come down to the app not appearing yet, choosing a one-time open action, or testing from a browser instead of a local file.
PDF Engineer does not appear in the list
Open PDF Engineer once, close and reopen Settings, then search for .pdf again. If it still does not appear, use the File Explorer Open with method from a real PDF file.
A browser still opens PDF links
The Windows .pdf default controls local PDF files. A browser may still preview PDFs opened from web links until you download the file or change that browser's PDF settings.
Only one PDF opened in PDF Engineer
You may have selected Just once. Repeat the File Explorer steps and choose Always so Windows applies the choice to all PDF files.
Settings are managed by your company
Some managed Windows devices restrict default app changes. If the Default apps screen is locked down, ask your IT administrator to assign PDF Engineer for the .pdf file type.
Mechanical drawing workflow
Why make PDF Engineer the default?
Mechanical teams open the same kinds of PDFs all day: drawing packets, supplier markups, inspection prints, quote packages, release reviews, and ECO redlines. Setting the default removes the extra Open with step every time.
Once PDF Engineer is the default, double-clicking a local PDF takes you directly into tools built for GD&T, BOM balloons, leaders, flag notes, drawing symbols, and clean exported redline packets.
FAQ
Windows default PDF app questions
Can I make PDF Engineer the default PDF viewer on Windows 11?
Yes. Open Settings > Apps > Default apps, search for .pdf, then choose PDF Engineer as the app for PDF files.
Does this change my existing PDF files?
No. Changing the default PDF app only changes what happens when you open PDF files. It does not edit, move, rename, or convert the files.
Can I switch back to Microsoft Edge or Adobe Acrobat later?
Yes. Return to Settings > Apps > Default apps, search for .pdf, and choose the app you want Windows to use instead.
Do I need administrator access?
Usually, changing your own default app does not require administrator access. Installing PDF Engineer or changing defaults on a managed company device may require IT permissions.
Sources
Official Windows references
The Windows steps in this guide are based on Microsoft's current support documentation for default apps and the File Explorer Open with flow.
- Microsoft default app settings
Microsoft documents assigning default apps by file type from Settings > Apps > Default apps.
- Microsoft File Explorer Open with behavior
Microsoft documents the Open with flow and notes that choosing Always makes the selected app the default for that file type.