Hiya and welcome to SevenForums!

rb:
Code:
BugCheck 3B, {c0000005, fffff88004124e5f, fffff880081919a0, 0}
Probably caused by : dxgkrnl.sys ( dxgkrnl!DXGCONTEXT::Render+657 )
Code:
BugCheck 1000007E, {ffffffffc0000005, fffff88004007d6d, fffff880053e96a8, fffff880053e8f10}
Probably caused by : dxgmms1.sys ( dxgmms1!VidSchiSendToExecutionQueue+879 )
Code:
BugCheck D1, {30, 2, 0, fffff88000dae597}
Probably caused by : ataport.SYS ( ataport!IdeProcessCompletedRequests+27f )
Code:
BugCheck F4, {3, fffffa8003f8e7e0, fffffa8003f8eac0, fffff80002dd31e0}
c0000005 Exception in ext.Analyze debugger extension.
PC: 00007fff`7ecccf22 VA: 00000000`00000001 R/W: 0 Parameter: 00000000`00000000
Run sfc /scannow and chkdsk /r.
Install the latest updates from Windows Update.
Do the exact same steps for chkdsk /r but instead of typing in sfc /scannow type chkdsk /r.
http://www.sevenforums.com/tutorials/1538-sfc-scannow-command-system-file-checker.html
Install the latest DirectX drivers.
There's an 0xF4 code in your bugchecks. This could mean that there's a virus, a failing harddrive, failing RAM stick/s. Run SeaTools(DO NOT RUN FOR SSDS)
http://www.sevenforums.com/tutorials/313457-seatools-dos-windows-how-use.html Also run MemTest86+ for 8 passes. It must be MemTest86+.
http://www.sevenforums.com/tutorials/105647-ram-test-memtest86.html Scan your computer for viruses using Malwarebytes.
http://www.sevenforums.com/tutorials/338716-malwarebytes-anti-malware-free.html(My debugger failed to see what was the cause, but it is either csrss.exe or wininit.exe)
Hacb, it can be fixed by installing the latest updates from Windows Update and updating the DirectX drivers.