I have a 10 years old laptop running windows 10 version 1803 - Lenovo S-205
Here is a few thing I've done to make it work a bit faster:
1. Disable windows search service.
2. Disable windows defender real-time protection.
The problem here that this setting is applied for a limited period of time.
Some registry tweaks must be done to do it permanently.
Go to:
HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows Defender
Create key: DisableAntiSpyware DWORD with value 1.
The defender intensively exploits my weak HDD, so this tweak might be the most effective.