Microsoft kicked off a new promotion aimed at Windows XP customers, who have just one year to ditch the 12-year-old OS before it’s retired from support.

Small- and medium-sized businesses still running Windows XP and Office 2003—the latter also will be retired a year from Monday, on April 8, 2014—can purchase licenses to Windows 8 Pro and Office 2013 Standard at a 15 percent discount, Microsoft said on a promotional website.

Caveats apply: Customers must be running XP Professional, the Windows 8 Pro and Office 2013 Standard licenses must be purchased as a package via Microsoft’s Open License program, and the deal is capped at 100 licenses for each. The discount is good through June 30.

Microsoft pointed customers to a list of partners who will offer the Open License discounts.

On its Open License website, Microsoft quoted $188 for each Windows 8 Pro license, and $373 for each Office 2013 Standard license, for a total of $561. The 15 percent discount would lower each Windows-Office combo by $84 to $477.

Microsoft also again banged the XP retirement drum today in a pair of lengthly blog posts, which included links to documents and tools designed to assist migration. Those blogs also explained the impending end-of-life, and repeated well-rehearsed reasons why customers should make the move.