If you deleted all partitions, including the restore/recovery partition, then you'll need either recover CD/DVD discs , or a Windows 10 installation DVD.
First, I would check to see if you can find any recovery CD/DVD set you may have gotten with the computer. If you have those, use those first instead of trying to download a Windows 10 ISO.
If you are unable to find this, you can go to the link below, and download an ISO image file of the Windows 10 installation for the version of Windows 10 that this computer originally shipped with. I've also included a link to download imgburn, as you'll need to use that or another program to burn the ISO file to a recordable DVD.
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