*Severe* performance decrease & 100% CPU usage

[InternetKillTV]

Hiya!

It's been a super long time since I posted on here. My current PC is a desktop I purchased from PCSpecialist around 3 years ago now. The specs are:

AMD Phenom(tm) II X4 960T Processor 3.00Ghz
16GB ram
Nvidia GTX 680

The processor especially isn't particularly high end, but the build has always proven more than capable at handling anything and everything I throw at it and up until literally 4 days ago. All of a sudden I started experiencing severe freeze-ups every 20 - 30 seconds. They'd get worse and last longer when I moved windows between my two monitors but even without that the freeze's are consistent. It's as if everything stops responding although they don't actually stop responding. I can move my mouse just fine and anything I click or type will load or appear 2 - 10 seconds later when the freezeup has ended. It's incredibly frustrating as it's now affecting my ability to use the machine for anything other than menial tasks.

I noticed today that my CPU usage is at 100%. Not as an occasional spike but consistently at an entire 100% usage. The CPU isn't making any noise, the computer isn't hot and there are no out of place processes that are using up an abnormal amount of memory but still without fail the CPU usage remains at 100%. I'll post a screenshot below.

CPU Usage: http://i.imgur.com/O1N42a5.png

The problem remains after restarting, after leaving the PC off for a full day, and I'm completely unsure of what's causing it or what I can do to fix it. Any of you guys have any troubleshooting ideas? I'd like to avoid reinstalling Windows if possible.

Thanks

 

[ubuysa]

Initially I'd suggest you open the resource monitor and see what is using most of your CPU cycles. That would get you started at least.

 

[maxbor]

Could be a virus or antivirus software misbehaving. Most solutions seem to be to check resource monitor as ubuysa says and if that doesn't shed any light then you could try reinstalling windows and see if that sorts it. DO you have McAfee by any chance?

 

[Buzz]

Id start by running all the usual free system cleaners.

Links to downloads

Malwarebytes

CCleaner

Advanced SystemCare

Run all 3, one after the other. Do full system scans and clean out all the crud and any malware it finds. I find doing this fairly regular (twice a year) helps regardless of the main issue stated by OP.
Once the scans are complete and restarted then check system resource monitor. Also check task scheduler to see if anything is scheduled to start on boot or log on of user that shouldnt.

Open a command prompt and type Taskschd.msc to open task scheduler.

 

[Androcles]

Look in Task Manager under Processes tab

Click on CPU column header so that services get sorted based upon % usage

What's at the top ?

 

[InternetKillTV]

Malware bytes sorted it, thank you!