Problem with Windows 10 installation.
Problem with Windows 10 installation.
You have a Windows 8.1 license but can't locate the box. You were considering upgrading to Windows 10 and thought you could still use your 8.1 key, but the case is missing. There are options—paying $110 keeps it for now, or you might find alternatives. Steam is having trouble with this, but other stores may still work.
Updating doesn't require a key. For a new setup, proceed with the upgrade and then restore your system after activation.
You can run W10 without enabling it, and I've tried it on a single PC without noticing any issues.