I wanted to ask if Windows 10 is running on this notebook:
HP ProBook 4520s Notebook PC
So please answer only if you are sure.
I've already installed Windows 10 on older devices.
As long as it has 2GB for 32 bit or 4-8GB RAM for 4 64bit, it should work.
Best to throw the old HDD on the trash and obstruct a small SSD.