2 Answers

In order to uninstall a program press the 'Start' button, then open the 'Control Panel' and double click the option 'Programs and Properties' or "add/uninstall programs" then search for the program you wish to uninstall on the programs list, double click it and choose 'Uninstall'.

I advise you say more about the problem. In most cases, if you want to uninstall a software, you can go to control panel and if your icons or options are show in category, you can see Programs(under is there says uninstall a program). Click it and you will see your program list. There list all your programs and you may right click on the one then choose uninstall.

If you are talking about a rogue software which often stays firmly on computers and can also be considered as viruses, you need to do more work. Check this to see if this is what you need.