WASHINGTON — Senator Clinton is taking to the Web as she rolls out her campaign for the White House, beginning a three-night “conversation” with voters yesterday by criticizing Bush administration policies on Iraq, the response to Hurricane Katrina, and the environment.

Seated comfortably on a couch in her Washington home, Mrs. Clinton answered preselected questions posed by viewers from Westchester to Hawaii in a live, 30-minute “Web chat” broadcast on her campaign site. She will conduct the chats again tonight and tomorrow as part of a strategy to reach out directly to as many potential voters as possible and present herself in a format unfiltered by journalists and pundits. In an interview on the “CBS Evening News,” Mrs. Clinton said she had been “caricaturized to some extent” over her years as first lady and now as New York’s junior senator. She urged skeptical voters to “give me a chance” to prove herself as a presidential candidate.

Mrs. Clinton, in her Internet appearance, spoke about her middle-class upbringing in a suburb of Chicago, saying the presidency — or even the Senate — was not a lifelong ambition of hers. “I really didn’t think I would ever personally run for office,” she said.

Reiterating her support for universal health care, Mrs. Clinton attempted to turn her failure to enact it as first lady in the 1990s into an advantage. “Now some people might say, ‘Well senator, didn’t you try that before, back in 1993 and 1994?'” she said, before adding: “We were not successful, and we made a bunch of mistakes, and I’ve learned from all of that.”

The senator offered no new policy proposals in her Web chat, instead articulating her critique of the Bush administration and emphasizing her commitment to energy independence, the environment, and keeping America secure against terrorism. She repeated her opposition to the president’s plan to increase troops in Iraq and decried the administration’s response to Hurricane Katrina as “poorly organized” and “half hearted.” She also criticized the president’s position on global warming and said she would try to restart a “dialogue with the rest of the world” if elected.

She was animated at times, and also light-hearted, joking that a real answer to a question about energy would be “longer and more wonkish” than she had time for. She also sprinkled in a couple of non-policy questions. Asked about her favorite movie, she said, “I’ve had favorite movies at different stages of my life.” She listed “The Wizard of Oz” as her top choice during childhood, “Casablanca” as her pick for college and law school, and most recently “Out of Africa,” saying she was a fan of stars Meryl Streep and Robert Redford.

By focusing her early campaign so much on her Web site, Mrs. Clinton is seeking to take advantage of the latest political frontier, one that was not widely available when her husband first ran for the White House. Targeting the Democratic base, the Clinton campaign bought ads for the Web chats on several liberal blogs, including dailykos.com. The advertisements also appeared on more conservative blogs, including powerlineblog.com and captainsquartersblog.com.

Users visiting the Clinton Web site to watch the Web chat were asked to register with their e-mail addresses and zip codes, allowing the campaign to compile lists of activists that could be used for future organizing and fundraising. A Clinton spokesman, Howard Wolfson, also confirmed reports yesterday that Mrs. Clinton will not participate in the public campaign financing system in either the primary election, or, if she is nominated, the general election. The announcement sets the stage for a race to the top in what will surely be a record election for fund-raising and spending.

In 2004, both President Bush and Senator Kerry, the Democratic nominee, turned down public financing during the primaries but participated in the program during the general election.

Despite the recent entry of several other Democratic hopefuls, including Senator Obama of Illinois, into the 2008 race, Mrs. Clinton has dominated the political scene since announcing her candidacy on Saturday. She is keeping herself at the center of attention with a busy schedule of events and television interviews to highlight both her Senate work and her bid for president. After announcing health care legislation on Sunday, Mrs. Clinton yesterday morning joined other members of New York’s congressional delegation, including Senator Schumer, at ground zero to renew her call for more funding for responders to the September 11, 2001, terrorist attacks on the World Trade Center. The officials are holding a similar press conference today at the Capitol here aiming to increase pressure on President Bush to include the money in his budget. Some members of the delegation, including Mrs. Clinton, are bringing responders who have become sick since working at ground zero to the president’s State of the Union address tonight.

Mrs. Clinton sought to make an emotional appeal yesterday before a throng of reporters and camera crews standing near the entrance to the World Trade Center site at Church and Fulton streets.

“We want the president and members of Congress to see the faces of those who have suffered because of our negligence in refusing to take care of the people who responded to 9/11,” Mrs. Clinton said as she stood next to several former ground zero workers. “We want people to have to look into the eyes of these men and women and then say, ‘No, it’s not our responsibility to makes sure you have the health care you need to deal with these illnesses that came about because your country was attacked.'” The lawmakers have said since last month that federal funds to treat those afflicted by respiratory and other illnesses potentially caused by toxic dust at ground zero will run out by the summer if more money is not appropriated.