Twenty-five years ago today, the Dow Jones Industrials (DJINDICES:^DJI) suffered its worst one-day percentage loss in its illustrious history. As Fool contributor Alex Planes will look at in more detail later this hour, the "Crash of the Century" was unprecedented in its ferocity and prompted numerous changes to try to stave off future crashes. But even though stocks aren't crashing today, they're definitely not celebrating, either, as the Dow was down more than 100 points at 10:45 a.m. EDT.

Earnings continue to be a big driver of moves among Dow stocks. Last night, Microsoft (NASDAQ:MSFT) reported earnings that came in well below expectations. Revenue dropped 8%, and a 22% plunge in net income partially reflected an anticipated slowdown before the release of the Windows 8 operating system. But as we saw with Intel's (NASDAQ:INTC) earnings disappointment earlier in the week, PC sales have slowed, and if that trend continues, it won't matter what operating system is on a product that no one's buying. Investors apparently agree: The shares are down more than 2% in early trade.

General Electric (NYSE:GE) fell even more sharply, down about 2.5% after matching earnings expectations but falling short on the top line. GE still believes it can grow earnings for the full year by double-digit percentages, but the company is suffering from adverse currency effects and doesn't believe economic conditions will improve in 2013.

Finally, McDonald's (NYSE:MCD) topped the losers' list with a 3% drop after its own disappointing quarterly report. Weak revenue growth was the primary culprit, with same-store sales rising 1.9% -- the slowest rate since mid-2003. As with GE, a strong dollar hurt results, and analysts expect that tougher year-over-year comparisons will make it harder for McDonald's to sustain growth.

Fool contributor Dan Caplinger has no positions in the stocks mentioned above. The Motley Fool owns shares of General Electric, Intel, McDonald's, and Microsoft. Motley Fool newsletter services recommend Intel, McDonald's, and Microsoft. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.