download from Microsoft and create installation media which will prepare a bootable USB to do a clean install of Windows 10.  you can do it yourself and it is free. Download Windows 10 (microsoft.com)
I corrupted by CPU win 10 operating system. Can I download form dell site etc. to a usb and reinstalled from boot f12? I really messed up...thanks Or should I take to best buy or shop for reinstallation.
XPS 8900, reinstall Windows 10