i am a little confused by that question. are you asking if you can change the account settings (icon, password, priveleges) or are you asking about the Appearance (background, screensaver, theme)?
if its the account settings you want to change then follow these steps \/
goto Start, and open Control Panel
-then click on the User Accounts icon
-click on the account at the bottom that you want to change/delete.
-you can then change you account name, password, picture, and account type
if you want to change the appereance and themes follow these steps \/
first right-click on your wallpaper and click Properties
-to change the look of the programs list and open windows, change the theme from the drop-down menu under the Theme tab.
-desktop is where you change wallpaper
-screensaver is where your screensaver is changed
-under the Appearance tab, you can change the fonts, color, and style for open windows and buttons
-the Settings tab is used to change screen resolution
i hope this has helped. if it hasnt please clarify your question to the best of your ability and ill try my best to get you an answer