Win2PDF first writes to a temporary folder before copying to the destination folder.  If the permissions of the temporary folder are different than the destination folder, the file can inherit the temporary folder permissions instead of the destination folder permissions.  

Setting the permissions of the temporary folder to the desired permissions will resolve the problem. You can also set an environment variable named "WIN2PDFTEMP" to a temporary folder with the desired file access permissions.  This environment variable can be set using the "Win2PDF Admin Utility" available in the download section of the support web site at:

https://helpdesk.win2pdf.com/index.php?/Knowledgebase/Article/View/187/15/win2pdf-admin-utility-download

The easiest way to set the temp file so that all users have permissions to your PDF files is to set the location to your "shared documents" folder which is usually:

C:\Documents and Settings\All Users\Documents

To set this using the Win2PDF Admin Utility, click on the "Troubleshooting" tab, type your shared documents path in the text box under "Win2PDF Temporary Folder", and click "Apply."