Stuttering and lag after leaving computer on

[crimsonangel]

Ok so my problem is after leaving my computer on for extended periods of time or overnight when I come back to it, it behaves very lagy. For instance if I try to play music or watch a movie any sort of sound is filled with pops and stutters and the only way to fix things is to restart. My sound is routed via optical cable to an audioengine D1 Dac into my speakers. The next thing is when I play games if the computer has been on for a while and I go to play a game the frame rate will be very unstable and I notice quite a bit of choppiness, again restarting will alleviate this for a while.
At first I thought maybe something is taking up all my ram caused by some memory leak but when I open task manager only about 30 percent or so is being used. I also do have another problem that happens very rarely Ill be playing a game talking on Skype and all of a sudden everything freezes a stuttering noise comes out just as if its about to bluescreen but instead the screen mouse and keyboard become completely unresponsive so I cant click anything or access task manager and the screen remains stuck on the last image. The strange thing about this is the sound continues to work and I can still talk on Skype and the people im on Skype with can still hear me but other than that im completely frozen and am forced to hold the power button to power down and turn back on. Any solutions to this would be helpful thanks.

Specs
CPU: Intel Core I7 2600k
Mobo: Asus Maximus IV Extreme
Ram: 8 gigs Corsair Vengence 1600Mhz
Samsung 830 Series SSD 256GB
Western Digital Caviar Black 2TB
Graphics: Asus 680GTX TOP
PSU: Corsair AX750
Case: Corsair Obsidian 800D
CPU Cooler: Corsair H100i
OS: Windows 8 Pro 64bit
Monitor 1: Samsung series 9 S27B970D
Monitor 2: Asus VG248QE

 

[dodger46]

Have you tried hooking up your speakers via an audio cable from the Mobo Audio Jack to see if the DAC is causing the problem?

 

[crimsonangel]

Have you tried hooking up your speakers via an audio cable from the Mobo Audio Jack to see if the DAC is causing the problem?

I just got the dac a few days ago problem was happening before then, audio isn't the only thing that stutters though, as i said frame rates in games get very choppy and cant remain stable and even basic operating system tasks are jerky and no longer smooth.

 

[dodger46]

Have you tried hooking up your speakers via an audio cable from the Mobo Audio Jack to see if the DAC is causing the problem?

I just got the dac a few days ago problem was happening before then, audio isn't the only thing that stutters though, as i said frame rates in games get very choppy and cant remain stable and even basic operating system tasks are jerky and no longer smooth.

Right. Another area that could possibly cause these symptoms is heat, check your temps with Speccy/GPU-Z. Apart from that, only other suggestion is to use the Clean Boot method to try to isolate an App/process which is causing the problem.
http://support.microsoft.com/kb/929135/en-gb
The diagnosis method is similar to the Win 7 Clean Startup
http://support.microsoft.com/kb/331796
Reading both should put you on the right track. It's long-winded and time consuming, but that's the nature of diagnosing intermittent faults! No easy fixes.