One way of speeding up a PC is reducing the bloat of system startup. Some useless apps slow down a computer’s boot-up speed because these apps, although unused, are scheduled to load when the computer turns on. If you don’t mind keeping the programs but want to gain startup efficiency, run “msconfig” — a system-configuration utility in Windows 7 that will let you select individually which applications load when the computer powers up.
When some programs uninstall, they leave residual files, settings or folders on your computer. Although you can remove them manually if you wish, these lingering components will usually not affect your computer’s operation once the program itself is disabled or deleted.