Why Laptop runs out of memory?

Hello!

Asus Laptop runs out of memory.
It does it even if I just turn it on and let it sit.

Here is an example of 'physical memory used' vs. time:

I start computer and do not start any programs. Turn on Task Manager and observe physical memory usage:

12:10 – 1.76 GB
12:35 – 2.43 GB
12:54 – 3:18 GB
13:06 – 3:70 GB

If I look at processes sum of all memory used by all processes is significantly lower then 'physical memory usage'.

Please advice how to fix this.

Thank you

Thank you for your advice. Here is snapshot of the monitor.
The sum of all memory listed does not correspond to 'physical memory used(?)'

Process Explorer - what should I type in command line to evoke it?

Please saved file from process explorer. Note, I had to restart pc before I ran process explorer - memory got full. When I was saving the file memory was used ~ 2.5Gb - it creeps up after I start the pc.

Another 15 minutes and it will fill in - right now memory is at 3Gb already.
Numbers in process explorer look similar to numbers in task manager - and they significantly less then total memory used.
Like on picture i sent earlier; if we add all the memory usage numbers they will be maybe 25% of total memory used.

For reference, it not always was like that.
I had virus, asked specialist to remove it. He did removed the virus seemingly and in the process he likely adjusted settings or something. Now I have no virus but got that instead ...
I wish I understood what he did.