Windows 10: Laptop overnight has increased lag exponentially

Hi,2 days ago, my laptop started lagging a lot. It started with me waiting for 15-25 minutes to log in after putting on my laptop. After that, every browser also was lagging significantly more than before. I have tried closing start-up tasks, deleting old files, checking cpu and gpu levels which all appear to be fine, scanned the windows drive and ran the 'sfc /scannow' command on the command prompter.Please help, I am so confused how my laptop could become THIS laggy overnight

:)

 

Random lag spikes

Hi,

We would like to know more about your lag issue:

• What browser are you using when you experience a lag?
• Does the lag occur in a particular game?

In the meantime, we suggest you run the System Maintenance troubleshooter. Here are the steps:

• Press Windows Key + X.
• Click on Control Panel.
• Select Troubleshooting.
• On the left pane, click on View All.
• Click on System Maintenance to run the troubleshooter.

Looking forward to your response.

 

Best laptop under $800??

Well the last one I suggested seems to be the best for 650$

EDIT: to facilitate your search...

Laptop GFX benchmark list

Laptop CPU Benchmark list

 

Volume Fluctuations - Whenever I open a new tab or program the volume increases exponentially.

Original Title - Volume Fluctuations

Whenever I open a new tab or program the volume increases exponentially. The number doesn't change, like if I have it set to "8" it stays at "8", but the volume gets extremely loud. Whenever this happens I just adjust the volume, either by left clicking
the volume control on the task bar or by pressing Fn + F2 (which decreases the set volume). When I do this the volume reverts back to the regular volume level. I do not know how to fix this.