Upgrading hp pavilion 15

[Stino0925]

I am trying to upgrade my laptop with 32gb of ram and a 1 tb memory stick. I bought the parts from microcenter and I showed them my laptop. I got the parts and installed them started back up the laptop and it didn't have anything to boot from. So I put the old parts back in for now because I do not own another computer. Now I'm assuming I would have to download the windows installer on a flash drive to reinstall my new parts properly. (Im new to this) Can I please get some further instructions, I have a flash drive so where do I download the windows 11 installer and how do i put it on the flash drive, and how do I re-boot my laptop from the flash drive with the installer?

[Paul_Tikkanen]

You can use the HP cloud recovery tool to create a bootable USB recovery drive that will reinstall Windows, the drivers and the software that originally came with your PC.

Here is an info link for how to use the utility.  You will need a 32 GB USB flash drive to create the recovery media with.

HP Consumer PCs - Using the HP Cloud Recovery Tool in Windows 11 and 10 | HP® Customer Support

You can download the software from the Microsoft Store.

HP Cloud Recovery Tool - Microsoft Store Apps

If you have to use the utility on another PC, you will need to enter your notebook's product number in the tool's search window in order to proceed to make the recovery media. 

Your PC's product number is: 1S8F3UA#ABA

The instructions to boot from the flash drive on the above link are rather vague.

To boot from the USB recovery drive, have it plugged into your PC's USB port.

Turn on or restart the PC.

Immediately press/tap the ESC key to get the menu of options.

Select the F9 boot options menu and from that, select the USB recovery flash drive and press the Enter key.