NOTE: You do not need to change the computer time zone or change the computer clock for time changes due to Daylight Savings Time. As long as you have the correct time zone and location specified for your computer, Windows will change the clock automatically when Daylight Savings Time begins and ends. Windows is also "aware" that some regions within time zones observe Daylight Savings Time during different dates, or not at all.

For example, if you set your Windows time zone to "Mountain Time (UTC-7:00)", Windows will adjust the clock at the beginning and end of Daylight Savings Time. However, if you set your Windows time zone to "Arizona (UTC-7:00)", Windows will not adjust the clock during Daylight Savings Time, since DST is not observed in Arizona.

To change the time zone, find the date and time displayed on your Windows screen, typically in the lower-right corner:

When this window opens, click on "Change date and time settings":

When the "Date and Time" dialog box opens, click "Change Time Zone":

That will give you a large list of different timezones to choose from:

Note that some time zones for countries are listed only by their major city; for example to select the time zone for the country of Uruguay, pick "(UTC-03:00) Montevideo" (Montevideo being the capital of Uruguay).

That's all that's needed! Save travels, and don't forget to change your time zone back again when you come home ;-)