This error usually appears when you try to write data into a folder without the appropriate permission. This is the case when you try to uninstall a program without permission. To fix this problem, try uninstalling the application from the Administrator account. To log in to it, go to Start > All programs > Accessories > right click on Command Prompt and select Run as Administrator. In the new CMD window, type
net user administrator /active:yes and press Enter. After you did this, reboot your computer and log in to your Administrator account. You should be able to uninstall the program from there without any difficulties.