CPU gets stuck at 100% usage randomly

[bratecybex]

Hello,
I bought a cheap PC maybe 7 years ago and it has Celeron D326 @2.53 GHz, integrated graphics and 2GB of RAM. It wasn't the best even when it was new, but it was usable. At one point, few years ago, it slowed down - and since then it barely works. I changed OS a few times since then, but it didn't get any better. Now it can't even run youtube videos properly.
I noticed that, usually, RAM usage remains low but CPU usage often jumps to 100% and remains there for some time and PC becomes unusable or very slow. After maybe a minute or two, it drops to normal again for a shorter amount of time before it rises to 100% again.
Is there anything I could do?

 

[MrN1ce9uy]

Nothing changed about the CPU. But everything has changed about the code that it processes. That is why computers seem to slow down over time, the programs and code they process becomes more complex.

On the other hand, malware can infect the system and slow things down and cause high CPU usage. But if you said you changed operating systems with a clean format of the old, and it is still slow I imagine it's just the old Celeron D just isn't up to the task of modern computing.

There's a couple of old Pentium 4 machines where I work, and I can say they just aren't fast enough to keep from lagging during web browsing. Celeron D is no different, single-threaded socket 478.