What is dirty memory?

Dirty memory is the memory, RAM,  is supposed to release back to the system after being used by certain processes, because of not all application designed perfectly.  After a while, more and more dirty memory which supposed to release back to the system for new coming processes build up, so available memory/RAM getting short. This is a reason why You should reboot your computer some time. I reboot mine at least once every two days.

Fresh install of Windows 10 installs home instead of Pro

Have you had a similar problem with the installation Windows 10 Pro below?
“Laptop came with Windows 10 Home pre-installed. I upgraded this to Pro using the Microsoft Store.
When doing a clean install it installs Home without prompting, instead of Pro. Is there a way to force it to install Windows 10 Pro on a clean install?”

Solution: get a copy of DVD Windows 10 Professional 64 bit with embedded Genuine keys from [shop.allogics.com]