It depends on what you need to uninstall.
In Windows, how do I uninstall programs?
Beginning with Windows 95, all versions of Windows have an Add/Remove Programs control panel that facilitates uninstalling programs. In DOS and Windows 3.1, you were required to manually delete the folders, files, and autoexec.bat and config.sys entries in order to uninstall a program. However, in Windows 95 and later, you are not required to manually uninstall programs, and UITS doesn't recommend it.
The following instructions describe how to use the Add/Remove Programs control panel:
Windows Vista
From the Start menu, select Control Panel.
In Classic View, double-click Programs and Features. If using the Control Panel Home view, under "Programs", click Uninstall a program.
Select the program you want to remove, and click Uninstall. Alternatively, right-click the program and select Uninstall.
Windows XP in the default XP view
From the Start Menu, select Control Panel.
Click the Add or Remove Programs icon.
Select the program you wish to remove and click Remove.
Windows 2000 and XP in Classic View
From the Start menu, select Settings, and then Control Panel.
Double-click the Add/Remove Programs icon.
Select the program you wish to remove and click Add/Remove.
Using the Uninstall program from the Start menu
If the program you wish to uninstall is not listed among the installed programs, there might be an uninstall program for that item on the Start menu. You can look for such an option by following the instructions below:
From the Start menu, select Programs or All Programs.
Find the folder for the program you wish to uninstall and highlight it.
In many cases, on the menu that appears, you will see an uninstall option.
If the program has neither a listing in the Add/Remove Programs control panel nor its own uninstall program, you might try installing it again, and then trying to uninstall it via the Add/Remove Programs control panel.
If all the above suggestions fail, call the technical support number for the program and ask how you can uninstall it.