Microsoft has offered up some fresh details about the upcoming release of Office for Windows RT. In a post at the Office Next blog yesterday, the company re-confirmed that the tablet-focused productivity software optimized for ARM processors will come pre-installed on Windows RT devices at no extra cost, but it will be a preview version of Office Home & Student 2013 containing Word, Excel, PowerPoint and OneNote.

It's unclear if this means Microsoft expects the software to be buggy and crash prone initially, or if some features will be missing. That said, all customers will eventually receive an upgrade to the final version of the suite for free via Windows Update starting in early November through January depending on their language.

Office Home & Student 2013 RT will only run in Windows RT machines and will not be sold as a stand-alone product. It was built from the same code base as the versions of Office for computers running traditional x86 chips from Intel and AMD, and offers "the vast majority" of the features available in the full PC version.

Microsoft says Windows RT tablets have special requirements for security, reliability, and battery life, thus some differences with x86 version are unavoidable. Here's the list of features missing for ARM users:

  • Macros, add-ins, and features that rely on ActiveX controls or 3rd party code such as the PowerPoint Slide Library ActiveX control and Flash Video Playback
  • Certain legacy features such as playing older media formats in PowerPoint (upgrade to modern formats and they will play) and editing equations written in Equation Editor 3.0, which was used in older versions of Office (viewing works fine)
  • Certain email sending features, since Windows RT does not support Outlook or other desktop mail applications (opening a mail app, such as the mail app that comes with Windows RT devices, and inserting your Office content works fine)
  • Creating a Data Model in Excel 2013 RT (PivotTables, QueryTables, Pivot Charts work fine)
  • Recording narrations in PowerPoint 2013 RT
  • Searching embedded audio/video files, recording audio/video notes, and importing from an attached scanner with OneNote 2013 RT (inserting audio/video notes or scanned images from another program works fine)

The company will disclose more details on October 26, the day Windows 8 and Windows RT officially debut.