New PC Cooling Problems

Hi guys. I just bought a PC from ibuypower and I'm having some problems with crashes. I will leave specs below. The computer runs fine for hours outside of games. The computer runs fine in BF4 windowed mode, but only gets about 60fps on all ultra and 4x anti aliasing and hbao. I think the lowish frame rate here is due to the windowed mode, but I'm not sure. When I go full screen, I get 115fps on the same settings in the same conditions, but after 10 seconds the GPU fans go crazy, and after 20 seconds the computer will fully crash. I haven't tried any other games except for crysis on all very high settings in full screen, and I get the same crash. The computer will run bf4 fine in windowed for hours.... I think this problem is related to the cooling fans, because I haven't over clocked my CPU, so my stock heatsink should be fine. Also haven't over clocked GPU or ram. All latest drivers and win 8.1. Crashes happen with AMD Overdrive on or off, and automatic fan control as well as manual. Is this being caused by inadequate fans? If so, what should I buy with cyber Monday coming up, and how do I install it? Is it safe to run for 1-2 hour sessions daily with the case open until I have the problem resolved? (I havent tried this yet because I don't know what dust would do to my computer. Specs are below. Thanks for any help.

Case 1 x AZZA Atlas Gaming Case - Black
Case Lighting 1 x Liquid Neon Thunder Pattern Light - Red
iBUYPOWER Labs - Noise Reduction X
iBUYPOWER Labs - Internal Expansion X
Processor 1 x Intel® Core™ i7-4770K Processor (4x 3.50GHz/8MB L3 Cache) - Intel® Core™ i7-4770K
iBUYPOWER PowerDrive 1 x PowerDrive Level 2 - Up to 20% Overclocking
Processor Cooling 1 x Liquid CPU Cooling System [Intel] - Standard 120mm Fan
Memory 1 x 16 GB [8 GB x2] DDR3-1600 Memory Module - Corsair or Major Brand
Video Card 1 x AMD Radeon HD 7990 - 6GB
Motherboard 1 x MSI Z87 G41 PC Mate -- 2x PCIe 3.0 x16, 2x USB 3.0, HDMI after 6/10
Intel Smart Response Technology X
Power Supply 1 x 850 Watt - AZZA Dynamo 850W
Primary Hard Drive 1 x 120 GB ADATA SSD - Single Drive
Data Hard Drive 1 x 1 TB HARD DRIVE -- 32M Cache, 7200 RPM, 6.0Gb/s - Single Drive
Optical Drive 1 x 24x Dual Format/Double Layer DVD±R/±RW + CD-R/RW Drive - Black - FREE Upgrade to BLU-RAY Reader Combo Drive for Primary Optical Drive
2nd Optical Drive X
Flash Media Reader / Writer X
Meter Display X
Sound Card 1 x 3D Premium Surround Sound Onboard
Network Card 1 x Onboard LAN Network (Gb or 10/100)
Operating System 1 x Windows 8.1 + Office 365 Trial [Free 30-Day !!!] 64-bit
Keyboard 1 x iBUYPOWER Standard Gaming Keyboard
Mouse 1 x iBUYPOWER Standard Gaming Mouse