You don't need the original installation media that came with the laptop.

The Dell XPS 17 9720 shipped with a Windows digital license stored in the system firmware (UEFI). During a clean installation, Windows 11 will automatically detect the license and activate itself once it's connected to the internet, provided you install the same edition (Windows 11 Pro).

You have several reinstall options:

• Windows Reset: Go to Settings → System → Recovery → Reset this PC. You can choose either:

  • Cloud download (downloads a fresh copy of Windows from Microsoft), or

  • Local reinstall (uses existing recovery files).

• Dell Recovery: If the recovery partition is still intact, you can boot into SupportAssist OS Recovery or use Dell OS Recovery Tool to restore the factory image, including Dell drivers and utilities.

• Clean installation: Download the Windows 11 Media Creation Tool from Microsoft, create a bootable USB drive, boot from it, and install Windows 11 Pro. You can skip the product key prompt by selecting "I don't have a product key"—Windows will activate automatically after installation.

That said, a clean reinstall is unlikely to fix consistently high ping times unless the cause is software-related. Before reinstalling, it's worth checking:

• Whether the issue occurs on multiple networks.

• Whether it happens over both Wi-Fi and Ethernet.

• Network adapter driver and BIOS updates from Dell.

• Whether high latency is due to packet loss, power management, VPN/security software, or a specific application.

If the problem persists even after a clean Windows installation, it's more likely to be a driver, hardware, router, or ISP issue than Windows itself.

If the system shipped with Windows 11 and was not upgraded from Windows 10,

https://www.dell.com/support/kbdoc/en-us/000192698/reset-or-reinstall-windows-11-on-your-dell-computer

@ejn63​

Thank you. Great reference. This points out that I should have been creating restore points along the way. Still reading through the materials. 

My laptop came with Window 11 Pro. The only thing I did not like about the initial setup process was that it assumed I wanted to use my Microsoft account and it created a username for me without asking me to confirm or change it. There didn't seem to be a way to setup a local account with the initial setup.

Windows 11 requires an MS account by default.  While there are ways to bypass the requirement, they require access to a command line during setup - not something most users are ready for.

https://learn.microsoft.com/en-us/answers/questions/2243108/how-to-setup-windows-11-without-a-microsoft-accoun