Does My Applications Slow Down My Computer?

Hello I have a windows 8.1 computer and I am trying to use it to the fullest and fastest it can be. One of the ways I use the computer is play using Steam. I have about 50 gigabytes worth of space used and have about 610 gb remaining. Will having my games and other stuff slow down my computer?

Tech Support Guy System Info Utility version 1.0.0.2
OS Version: Microsoft Windows 8.1, 64 bit
Processor: Intel(R) Core(TM) i3-3120M CPU @ 2.50GHz, Intel64 Family 6 Model 58 Stepping 9
Processor Count: 4
RAM: 3980 Mb
Graphics Card: Intel(R) HD Graphics 4000, -2041 Mb
Hard Drives: C: Total - 703461 MB, Free - 656306 MB;
Motherboard: TOSHIBA, Portable PC
Antivirus: Windows Defender, Disabled

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