System rebooted caused by hal.dll

I have finished building my own pc last months but my pc rebooted randomly. My pc work well in the first few days but when I start downloading documents from a certain websites, my pc rebooted and the situation continuted. My pc usually crashed when idle but never crashed when it is in used even I am playing games with my pc.Here is the information from the eventlog.

The computer has rebooted from a bugcheck. The bugcheck was : 0x0000007f (0x0000000000000008, 0xffffd00024f64130, 0xffffd000257c7fe0, 0xfffff802b4a0e57a)
System

- Provider

[ Name] Microsoft-Windows-WER-SystemErrorReporting
[ Guid] {ABCE23E7-DE45-4366-8631-84FA6C525952}
[ EventSourceName] BugCheck

- EventID 1001

[ Qualifiers] 16384

Version 0

Level 2

Task 0

Opcode 0

Keywords 0x80000000000000

- TimeCreated

[ SystemTime] 2015-05-28T04:53:38.000000000Z

EventRecordID 2623

Correlation

- Execution

[ ProcessID] 0
[ ThreadID] 0

Channel System

Computer JKHY

Security


- EventData

param1 0x0000007f (0x0000000000000008, 0xffffd00024f64130, 0xffffd000257c7fe0, 0xfffff802b4a0e57a)
param2 C:\Windows\MEMORY.DMP
param3 052815-27328-01

System information:
intel core i5 4690
nvidia gtx 970
Asrock b85m pro 3
team elite 8gb ddr3 cl11

I haven't overclocked and I've checked my ram(memtest86+) and hardisk and there aren't any error found.

Can anyone help me, please?