The Dow Jones industrial average fell 59 points to 12,756 on Tuesday, a loss of about half a percent.
The Standard & Poor's 500 index gave up five and a half points to end at 1,375. The Nasdaq composite fell 20 points to 2,884.
Microsoft was the biggest loser in the Dow, giving up 3 percent. The head of the company's huge Windows division left just weeks after the company launched Windows 8, the latest update to its operating system.
Indexes drifted up and down in uneven trading as traders worried about testy budget talks in Washington and a decision in Europe to delay the latest aid package for Greece.