If you are fortunate, i.e., your computer is less than 3 years old, there might be a way to either order a USB memory-stick from HP that contains the Windows Installer for the originally-shipped operating system, or a "cloud-based" method of downloading the same software.
If your disk-drive is the original, there should be a copy of the "Windows Installer" in a hidden partition of your disk-drive.
Also, there may be a utility program on the 'C:' drive that you can use to copy the "Windows Installer" onto a USB memory-stick (or to burn a few DVD-recordable disks).
More details from you will get you more-specific advice.
This topic has been archived. Information and links in this thread may no longer be available or relevant. If you have a question create a new topic by clicking here and select the appropriate board.