The Dow Jones Industrial Average (DJINDICES:^DJI) had added 103 points as of 11:30 a.m. EDT. Dow Jones component Microsoft (NASDAQ:MSFT) was the index's biggest gainer, as hope for a new version of the popular Office software sent shares surging. At the same time, shares of Microsoft partner and former Dow stock Hewlett-Packard (NYSE:HPQ) posted a solid 3.7% rally following some positive analyst comments. Apple (NASDAQ:AAPL) shares rose modestly as the company made a few minor adjustments to its product lineup.

Inflation data comes in below expectations
Perhaps helping to fuel the Dow Jones rise, U.S. inflation numbers came in below expectations on Tuesday, suggesting that the Federal Reserve may be justified in continuing to provide monetary support to the nation's economy.  The Consumer Price Index, a measure of inflation, rose only 1.1% on a year-over-year basis, less than the 1.2% that economists had anticipated. Core CPI, a preferred measure that doesn't include volatile goods such as food and fuel, rose 1.6%; that was in line with economists' expectations.

With inflation stable, or even weaker than expected, the Fed need not be in any rush to tighten monetary policy too hastily. As long as inflation remains subdued, the central bank may continue to slowly reduce its monthly bond purchases, rather than cutting them aggressively.

Microsoft will roll out a new version of Office later this month
Microsoft shares gained more than 4% in morning trading -- a significant move for a company valued at more than $300 billion. The Verge reported that Microsoft will roll out Office for Apple's iPad later this month, opening up the software to a market that has been forced to accept second-rate Office alternatives. Analysts have been calling for Microsoft to release Office for the iPad for months, arguing that it was missing out in billions of dollars' worth of revenue. If Microsoft does take this step, it could see subscriptions to its Office 365 program increase significantly almost overnight.

Hewlett-Packard boosted by analyst upgrade
Hewlett-Packard is one of Microsoft's largest customers, buying millions of Windows licenses for sale on its PCs. HP shares rose after Barclays upgrade the company to overweight from neutral. Barclays believes that Hewlett-Packard's server division will benefit from IBM's sale of its competing low-end server business to Lenovo.

Apple makes slight changes to lineup
Apple's stock rose 0.5%, less than the broader Dow Jones index. On Tuesday, Apple replaced the iPad 2 with the iPad 4 in its lineup, while rolling out an 8 GB version of the iPhone 5c in Europe.

The iPad 4 has largely the same design as the iPad 2, but it packs a sharper screen and more powerful internals. At $399, Apple is offering it for the same price as the iPad 2, which has now been discontinued. The 8 GB iPhone 5c isn't replacing another phone, but does start at a lower price than the versions of the phone packing more internal storage, and could entice some consumers on a budget.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.