Downloading applications that you don't know or have no idea what they do could be a reason why your computer is slow. Outdated software, in most of the cases, does not have an impact on your system's performance high enough to slow it so much. Please visit Add/Remove Programs in Control Panel and remove everything you don't know, then perform a restart of your computer.
A good solution would be that you also perform a cleaning operation using a software like CCleaner which scans your computer in an intelligent way, removing all that is not necessary regarding temporary files, corrupted and obsolete registry entries and so on.
Download and install the application, and use the buttons on the left and clean your computer. A computer restart is also recommended after these operations.
