The Dow Jones Industrial Average (^DJI 0.06%) is putting on a good show again today, up 40 points as of 1:50 p.m. EST. PC chip maker Intel (INTC -1.79%) and system builder Hewlett-Packard (HPQ -0.25%) are among the biggest winners on the 30-ticker index, gaining 1.3% and 1.5%, respectively. Looking further afield, mobile-phone veteran Nokia (NOK 3.60%) is absolutely crushing it today, jumping 17% on surprisingly healthy Windows-based phone sales.

Given this market backdrop, how in the world did Microsoft (MSFT -1.84%) manage to be the Dow's biggest dog today, falling 1.3%? All of its most important partners are going gangbusters. Shouldn't they drag Redmond along for the joyride almost by default?

Oh, but the market is never quite that transparent. Microsoft plunged on some personal bad news -- namely, a downgrade from influential investment bank Morgan Stanley. Analyst Adam Holt lowered his rating from "buy" to "hold" this morning. He still believes the stock is undervalued, but not by a wide enough margin to be worth the risk of parking your money there.

The introduction of the Windows 8 operating system has failed to re-ignite stalled PC sales, and the corporate upgrade cycle stalled because Windows 7 was just so darn effective in replacing the age-old Windows XP platform.

Mobile sales need help from app developers, because the current slate of high-quality apps for Windows 8 tablets isn't very impressive. Porting the Office suite to Apple (AAPL -0.57%) iPads could provide a long-term catalyst, but Microsoft hasn't announced any such effort yet. Even Congress could help by lowering the tax burden of bringing home some of Mr. Softy's $50 billion of overseas cash holdings -- but again, Holt doesn't expect this to happen anytime soon.

So Microsoft is pressing its nose against the glass to gaze longingly at several potential catalysts that are doing nothing to help it -- and down the stock goes.