Don't want to upgrade to Windows 10? Too late you've missed your chance!
If you didn't take up Microsoft's offer of a free Windows 10 upgrade then you've missed your chance. You now have to pay. There is apparently still a free get out if you use the Assistive technologies in Windows such as magnified fonts etc.
What I said before:
You may find, if you are running Windows 7 or 8 or 8.1 that you get plagued with with exhortations to upgrade to Windows 10. There may be reasons why you don't want to upgrade to Windows 10 but whatever they may be wouldn't it be nice if you could switch off these notifications to upgrade? Follow the links and install either of these two options. Not both. Neither are difficult to implement do but if you are not sure then ask someone who can install one of these two options for you.
PS Using a PC with Windows XP? If so You shouldn't be reading this and accessing the internet or email. Windows XP is not safe or secure. Microsoft does not support Windows XP with security updates any more.