I purchased a copy(physicall but with a key) of Win10, but I have no optical drive.

[smithliam2001]

How do I install windows on a pc I'm building? I have this physical copy with a key for Windows 10 for OEM software. I have no optical drive. How do I install it?

 

[bignastyid]

You can use Microsoft's media creation tool to download win 10 and create a bootable usb flash drive.
https://www.microsoft.com/en-us/software-download/windows10/

 

[captaincharisma]

only way to install it is to get a copy of the windows 10 version you have and put it on a USB stick. if you have access to another computer you can download the media creation tool for MS website and use it to load windows 10 on a USB stick. the USB stick will have to be at least 4GB for the install

 

[wpgwpg]

You could also buy a USB CD/DVD external drive. They aren't expensive (under $30) and will probably come in handy in the future.

Good luck.