File format guides
Straightforward help for opening, understanding and safely viewing legacy office files.
Outlook and email guides
What is a Winmail.dat file?Understand TNEF and extract hidden attachments.What is an MSG file?Understand Outlook’s single-message format.How to open an MSG fileView email details and attachments.Open MSG files on MacPractical options without Windows.How to open an EML fileUse a browser or desktop email app.Open EML files in GmailPreview, attach or forward saved email.
Microsoft Project guides
What is an MPP file?Understand the format and the information it contains.How to open an MPP fileView a project without installing Microsoft Project.Supported MPP filesFile requirements, limits and compatibility.MPP troubleshootingFix common upload and parsing problems.MPP views explainedGantt, task, resource, calendar and network views.File securityHow temporary uploads and browser data are handled.
Document guides
What is an XPS file?Understand Microsoft’s fixed-layout document format.How to open an XPS fileView XPS and OXPS documents online or enable the Windows app.XPS Viewer for Windows 10 and 11Use the optional Microsoft viewer or open XPS in a browser.How to open an OXPS fileView OpenXPS files and understand compatibility differences.