SVCHOST Runs Over 200k, System Is Slow

Hi, sorry if I'm overreacting but I suspect something is wrong with the PC. SVCHOST has been known to raise to over 400k in the past but usually it sits over 200k and rises during games until they freeze every few minutes, unlike my laptop which runs at 40k~. Games and browsers have slowed down considerably but Norton has not found any infection. I was wondering if you could help me find any problems that have gone unnoticed. Thanks very much in advance.

Tech Support Guy System Info Utility version 1.0.0.2
OS Version: Microsoft Windows 7 Home Premium, Service Pack 1, 64 bit
Processor: Intel(R) Core(TM) i5-4670K CPU @ 3.40GHz, Intel64 Family 6 Model 60 Stepping 3
Processor Count: 4
RAM: 8130 Mb
Graphics Card: NVIDIA GeForce GTX 660, -2048 Mb
Hard Drives: C: Total - 476837 MB, Free - 146969 MB; D: Total - 99 MB, Free - 84 MB;
Motherboard: ASUSTeK COMPUTER INC., Z87-K
Antivirus: Norton Internet Security, Updated and Enabled