Although first settled by Europeans in 1851, Windsor was not incorporated until July 1, 1992.
As of the census of 2000, there were 22,744 people, 7,589 households, and 5,775 families residing in the town. The population density was 3,372.7 people per square mile (1,302.9/km²). There were 7,728 housing units at an average density of 1,146.0/sq mi (442.7/km²). The racial makeup of the town was 79.00% White, 0.78% African American, 1.48% Native American, 2.29% Asian, 0.14% Pacific Islander, 12.42% from other races, and 3.89% from two or more races. Hispanic or Latino of any race were 23.58% of the population.
There were 7,589 households out of which 43.3% had children under the age of 18 living with them, 63.8% were married couples living together, 8.4% had a female householder with no husband present, and 23.9% were non-families. 18.6% of all households were made up of individuals and 9.2% had someone living alone who was 65 years of age or older. The average household size was 2.98 and the average family size was 3.40.
In the town the population was spread out with 30.8% under the age of 18, 6.5% from 18 to 24, 31.8% from 25 to 44, 19.8% from 45 to 64, and 11.1% who were 65 years of age or older. The median age was 35 years. For every 100 females there were 96.4 males. For every 100 females age 18 and over, there were 92.5 males.
The median income for a household in the town was $63,252, and the median income for a family was $67,992. Males had a median income of $46,553 versus $33,330 for females. The per capita income for the town was $24,336. About 2.9% of families and 5.1% of the population were below the poverty line, including 5.3% of those under age 18 and 7.4% of those age 65 or over.
In the state legislature Windsor is located in the 2nd Senate District, represented by Democrat Pat Wiggins, and in the 1st Assembly District, represented by Democrat Patty Berg. Federally, Windsor is located in California's 1st congressional district.