lunyone :
Well there are several factors, but usually when you have the computer shutdown after installing a new GPU it usually points to the PSU not having enough power to run the system under the conditions it is running under (maybe higher temps in the case due to the new GPU).
Normally I'd say the PSU should be fine, but what are you complete specs of your system, so we can help you out?
Hope this is what you're asking for, don't know too much about this stuff
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System Information
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Time of this report: 6/23/2015, 22:14:19
Machine name: PAC-PC
Operating System: Windows 7 Professional 64-bit (6.1, Build 7601) Service Pack 1 (7601.win7sp1_gdr.150316-1654)
Language: Spanish (Regional Setting: Spanish)
System Manufacturer: Gigabyte Technology Co., Ltd.
System Model: To be filled by O.E.M.
BIOS: BIOS Date: 01/28/13 13:43:06 Ver: 04.06.05
Processor: AMD FX(tm)-8350 Eight-Core Processor (8 CPUs), ~4.0GHz
Memory: 6144MB RAM
Available OS Memory: 6104MB RAM
Page File: 5104MB used, 7103MB available
Windows Dir: C:\Windows
DirectX Version: DirectX 11
DX Setup Parameters: Not found
User DPI Setting: Using System DPI
System DPI Setting: 96 DPI (100 percent)
DWM DPI Scaling: Disabled
DxDiag Version: 6.01.7601.17514 64bit Unicode
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DxDiag Notes
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Display Tab 1: No problems found.
Sound Tab 1: No problems found.
Sound Tab 2: No problems found.
Input Tab: No problems found.
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DirectX Debug Levels
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Direct3D: 0/4 (retail)
DirectDraw: 0/4 (retail)
DirectInput: 0/5 (retail)
DirectMusic: 0/5 (retail)
DirectPlay: 0/9 (retail)
DirectSound: 0/5 (retail)
DirectShow: 0/6 (retail)
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Display Devices
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Card name: ATI Radeon HD 4800 Series
Manufacturer: Advanced Micro Devices, Inc.
Chip type: ATI display adapter (0x9440)
DAC type: Internal DAC(400MHz)
Device Key: Enum\PCI\VEN_1002&DEV_9440&SUBSYS_E850174B&REV_00
Display Memory: 3299 MB
Dedicated Memory: 503 MB
Shared Memory: 2796 MB
Current Mode: 1360 x 768 (32 bit) (60Hz)
Monitor Name: Generic PnP Monitor
Monitor Model: SONY TV
Monitor Id: SNY9C01
Native Mode: 1360 x 768(p) (60.015Hz)
Output Type: HDMI