[SOLVED] PC been really glitchy and buggy after i updated my windows 10

[using google in BSOD]

this been happening since yesterday. (on my first PC)

first, it restarts at the first 3 startup at the day
then taskbar (including buttons on it) not responding unless i restart the system.
then flickering screen when running 2 applications at the same time.
CPU usage 100%
all usb ports not working.
low FPS although mid. level Gaming PC.
CPU fan rotate at high speed even if the temperature is low (30-45)
PC sometime won't turn off.
black screen after i clicked the search button.

so what's happening with this PC? and how do i fix this?

Thank you so much for helping!

edit:
more info:
just like the title, this all happened after i installed a cumulative update yesterday.

 

[kaipirinha]

This sounds a bit serious so better keep a backup of all your important files, if you didn’t already!

I can’t explain every step in detail right now, but if this is really just a windows issue (which is something we can’t be sure of) you can try the following:

-Windows updates can be uninstalled
-update drivers and software to make sure they are compatible with newer windows updates
-If windows system restore is activated for your system drive, you can return to a restore point way before the problems began. (you may loose some changes you made after this point but you will not loose documents).
-Try to repair windows without reinstalling it (you will keep all your programs and stuff)
-If you did the update to Windows 10 2004 recently, you can uninstall it and wait for a few months so maybe your issue will be fixed. If you did not install 2004 yet, you can try if it helps because it is basically a new windows installation and may replace broken files or configs.
-You can also reset or reinstall windows (loosing all your programs and files). Even Windows 10 can still break, especially if you did no clean install after a few years and several semi-annual updates on top of each other.

These are just some things you can do quickly and without changing hardware. I am just saying all this because you mentioned this happening after a Windows update. But this can also be a hardware issue having to do with CPU, motherboard, RAM or PSU. Maybe someone else can give better advice on hardware diagnostics.