An old laptop released many years, ago, HP Probook 4540s, here are the drivers for Windows 7 and Windows 10.
If you have lost the cd with the drivers, there is nothing to worry about.
HP has a software program that allows you to install all the drivers for this laptop within a few clicks.
The only thing you need first is to install the wireless LAN driver or you won’t have Internet access.
The wireless driver is called “aero” or something and can be found easily.
If you are installing Windows 10, the wireless network should work by default.
Also, on Windows 10, most of the drivers will be auto-installed with Windows, so you don’t need to bother with them.
If your Internet connection is working, go to this page.
This is a Firefox browser addon (plugin) that will detect the model of your laptop and will take you to the right place.
Once the device was detected, click on the resulted link, “Download drivers and software”, select your OS (Windows 7 or Windows 10), scroll to the last options from that page, “HP Support Assistant”.
Install that software.
It will help you to download and install all the drivers within a few clicks.
I recommend to install only the “critical” drivers if you are in a hurry or you will have to wait even 2-3 hours so the drivers to download and install.
Overall, this is is the easiest way to get the drivers for the HP Probook 4540s laptop.