PC makers pay a license fee to Microsoft to install Office Starter on new PCs. (It’s not available to ordinary retail customers.) You can use the Starter Edition with no restrictions or upgrade by purchasing a product key and activating the full version.

The collection of programs in Office Starter is Spartan, to say the least. You get Word Starter and Excel Starter, with a few extra tools. The PC maker is required to warn you that the Starter programs have u201creduced functionalityu201d and also include advertising.

Backstage view (which appears when you click File) has all the information and control over settings that you’ll find in the full Office editions, including yet another opportunity to purchase one of the full versions. Note the limitations are described much more kindly here than in the required disclosures from OEMs.

Look! It’s another Purchase button, with more details about what you’re missing. A noteworthy feature not found in full versions is the Take Office With You button, which installs Office Starter on a USB key that runs on any Windows PC.

The Starter edition of Word includes the full assortment of built-in templates and also offers access to every template available on Office.com from Microsoft and trusted third parties as well as from user-contributed sources.

Is that ad bar on the right side annoying? Better get used to it, because there’s no obvious way to remove it (that’s a cue for resourceful hackers if I ever saw one). In this case, using the new Search and Navigation pane was enough to push part of the current document out of the editing window.

Several advanced features from the full program are unavailable in Starter edition—especially Reviewing tools and the option to use macros and add-ins. But bread-and-butter features like these slick picture editing tools are identical to those in the for-pay versions.

Compare the ribbon in the Starter Edition (shown here) to the one in the unrestricted version of Excel and you’ll see that four tabs are missing, making it difficult to work with data connections and impossible to use PivotTables.

Compare the reasonably full Excel Starter interface with this truly stripped-down Excel Web App. The Insert tab has a mere two commands available, and many formatting and formula option are completely missing. (This screen is from a SharePoint site, but the SkyDrive app looks the same.)

As with Word, the feature set in Excel Starter is identical to the full version where it exists, as in these three tabs worth of commands for creating and editing charts.

One surprising new feature that is unique to Office Starter is the ability to create a portable version of Office that runs from a USB key. The setup program downloads some files and then configures a USB flash drive to run Office (on Windows only, naturally).