Help - Multiple PC Issues

First post on this forum, and not great technically - hope I can give enough information to get some help.

i have a custom built pc which is about 5 years old.
Upgraded recently to Windows 10 (which may or may not be relevant). Had increasing issues since which I seemed to get around by turning off & on, but as of today my PC is mostly unusable.

Cannot get onto the Internet which is, I think, network adaptor related - the wifi symbol in the task bar is replaced by a box with a red 'x'.
Cannot access device manager to resolve this. (This was an intermittent issue over the last 2 weeks which I was resolving by disabling/enabling the network adaptor).
Cannot access task manager.
Can access Network & Sharing Centre, but cannot access Change Adaptor Settings.

Can access some programmes - iTunes, Mcafee (ran a full scan which showed no issues).

2 days ago, on start up, Internet not connecting, everything very slow, and one of the fans in the box very loud.
had the box open & cleaned everything of dust - quite a lot. Seemed fine that day but not after.

Not sure what to do to be honest, hence coming on here. Any help would be greatly appreciated.

Jakally, I think that you have more than one problem

Is your rig built from the ground up for Windows 7?

Regardless, you already ran a deep anti-virus scan. Download the free Malwarebytes program and do a deep scan. These will both take a few hours, by the way.

There is more than one way to enter Task Manager. Right-click your taskbar; press Ctrl-Alt-Del at the same time; right-click the Start Button.

Vince Massi said:

Jakally, I think that you have more than one problem

Is your rig built from the ground up for Windows 7?

Regardless, you already ran a deep anti-virus scan. Download the free Malwarebytes program and do a deep scan. These will both take a few hours, by the way.

There is more than one way to enter Task Manager. Right-click your taskbar; press Ctrl-Alt-Del at the same time; right-click the Start Button.

Hello Vince, and thank you for your reply.
I'm pretty sure the system was built with windows 7 installed.
Unfortunately I cannot download the malware bytes program as the PC will not connect to the Internet.

I have tried the different ways of accessing task manager and none of them work. After a few minutes I get the following message ' C:/WINDOWS\system32\taskmgr.exe The service did not respond to the start or control request in a timely fashion'

Jak, I hate to say this, but you might have to revert to Win 7. Yes, you can still upgrade to 10 again.

Vince Massi said:

Jak, I hate to say this, but you might have to revert to Win 7. Yes, you can still upgrade to 10 again.

Ok. How do I do that?

um i dont know if this would work but
you could run a "sfc /scannow" in an administrative command prompt (without the quotes)

I cannot get a command prompt box to open. ( I could do this yesterday but not today).
I can open Settings but it will not let me go any further - I was trying to get into Update & Security section to look if I could revert to a previous point, or go back to Win 7.
I guess that the operating system is not operating?

The only things that work are installed programs such as iTunes etc...

When I try to open a command prompt, or Task Manager I get the following message.

This file does not have a program associated with it for performing this action. Please install a program or, if one is already installed, create an association in the Default Programs control panel.

Jak ,try to get into Cortana and type Revert to Windows 7.

It is possible that your custom-built rig used high-quality unsold parts for Vista or even XP.

I'm a big Windows 10 fan, but sometimes you just have to accept that your rig can't handle it.

Vince Massi said:

Jak ,try to get into Cortana and type Revert to Windows 7.

It is possible that your custom-built rig used high-quality unsold parts for Vista or even XP.

I'm a big Windows 10 fan, but sometimes you just have to accept that your rig can't handle it.

Typed it, 'Didn't find anything'.
Seems that I can't get into anything useful or do anything within the system.