Computer running slow

[Speedmc33]

GTX 970
I7 4790K
16 GB RAM

My computer used to run extremely fast with games like league of legends, CSGO, GTA. But in the past 3 months or so my mouse has been lagging, YouTube videos lag, league runs at 30 fps (on lowest settings).

I'm starting to get into CAD (SOLIDWORKS) and I really want a computer that can run it well. Windows is update and I can't seem to find out what going on. Any help would be great. Thanks in advance.

Edit: also worth noting that whenever I turn on the computer I get this blue screen Blue screen https://imgur.com/a/k1Tkd. The CPU/ Ram hovers between 1-30 percent while browsing. Not sure what causes the Chrome/ Youtube Lag.

 

[dklims]

Make sure to run some virus scanners and such. Also check your processes (Control + Shift + Escape) and look to see what is running in the background. My guess is you either have a virus or your harddrive my potentially be going.

Do you have a HDD or SSD harddrive?

 

[unreal9400]

Check Task Manager is the CPU running at full speed?

 

[dklims]

Check Task Manager is the CPU running at full speed?

On that note also check your power settings. You can push "Windows Key + X" and then select "power Settings"...make sure its on high performance which will allow your pc to use all cores / run at full speed.

 

[Speedmc33]

Make sure to run some virus scanners and such. Also check your processes (Control + Shift + Escape) and look to see what is running in the background. My guess is you either have a virus or your harddrive my potentially be going.

Do you have a HDD or SSD harddrive?

I use Malwarebytes and CCleaner very often. I have a 250GB Samsung 850 EVO ssd and a 1TB WD Harddrive

 

[Speedmc33]

Check Task Manager is the CPU running at full speed?

On that note also check your power settings. You can push "Windows Key + X" and then select "power Settings"...make sure its on high performance which will allow your pc to use all cores / run at full speed.

I just set it to high performance, I'll let you know if it solves the issue. The lagging is very on/off and not continuous.