Halp: What part keeps making my PC freeze?

Thank you in advance!

My PC keeps freezing up. The screen pauses, speakers hum, and the PC becomes inoperable, needing a hard restart.

It usually happens when I'm gaming, or watching a movie sometimes. It can a happen when browsing the internet sometimes.

I'm wondering what hardware might need an upgrade or is bottle-necking my PC. Is my CPU or GPU too old, or are they overheating? Is my RAM too small?

Thank you again in advance!

Here are my specs:

Processor Processor Intel(R) Core(TM) i7-3770 CPU @ 3.40GHz Manufacturer Intel Speed 3.4 GHz Number of Cores 4 CPU ID BFEBFBFF000306A9 Family 06 Model 3A Stepping 9 Revision 12

Memory RAM 8.0 GB

Video Card Video Card NVIDIA GeForce GTX 960 Manufacturer NVIDIA Chipset GeForce GTX 960 Dedicated Memory 4.0 GB Total Memory 4.0 GB Pixel Shader Version 5.1 Vertex Shader Version 5.1 Hardware T & L Yes Vendor ID 10DE Device 1401 Plug and Play ID VEN_10DE&DEV_1401&SUBSYS_36AD1458&REV_A1 Driver Version 10.18.13.6839

Operating System Operating System Microsoft Windows 7 Ultimate Edition Service Pack 1 (build 7601), 64-bit Service Pack 1 Size 64-bit Edition Ultimate Version 6.1.7601 Locale 0409

BIOS BIOS BIOS Date: 05/08/12 14:39:13 Ver: 06.10 Version American Megatrends Inc. 0610 Manufacturer American Megatrends Inc. Date 05/08/12

Sound Audio 1 Sound Device High Definition Audio Device Driver 6.1.7601.17514 Audio 2 Sound Device Logitech USB Headset Driver 6.1.7601.17514 Audio 3 Sound Device NVIDIA Virtual Audio Device (Wave Extensible) (WDM) Driver Audio 4 Sound Device NVIDIA High Definition Audio Driver 1.3.34.14

Drives DVD HL-DT-ST DVD-RAM GH10L CD HL-DT-ST DVD-RAM GH10L Drive 1 Size 698.6 GB Free Memory 313.3 GB Drive 2 Size 111.8 GB Free Memory 32.7 GB

Software Internet Explorer 8.0.7601.17514 Chrome 56.0.2924.87 Firefox Safari Java 7.0.90 Flash 24.0.0.0 DirectX 11.0 .NET 4.5.1 QuickTime Adobe PDF Reader 9.5.0.270

Power