You do not list the program you are trying to uninstall. If it is Norton or McAfee ignore the rest of this post and list the program you are wanting to remove. If not then you must first stop your old program from running before attempting to uninstall it. You can do this in Task Manager. Right click an empty space in your task bar at the bottom of the screen. Click Task Manager. Look in the processes tab and locate the program you are referring to. Then click Stop Process and proceed to remove it. If that does not work click Start >> Run and type in msconfig then hit run. Find the program in the Startup tab. Disable the program from running at Startup. Now Restart your computer then uninstall the program.