Still on Windows 7 or 8.x? If you are using assistive technologies, such as screen readers and voice recognition products, that provide essential accessibility to computers for those with significant vision, hearing, dexterity and mobility, language and communication, or learning needs - then you still can upgrade to Windows 10 for free by going to this link: Windows 10 upgrade

How about cleaning up the C:\Windows\WinSxS folder with features you do not need? Here is a Powershell One-liner, to remove those features not installed. If you ever need to get one of the features back, you can get them back with DISM (/enable-feature), Powershell (Install-WindowsFeature) or even the Server Manager GUI by pointing to a source. OK, here goes: Get-WindowsFeature | Where-Object {$._Installed -eq $false} | Uninstall-WindowsFeature -Remove