Security holes -- nicknamed "Spectre" and "Meltdown" -- could allow hackers to access your files.
Microsoft's update closes that gap but it also slows down your machine.
The company says Windows 10 users shouldn't notice much of a difference.
However, more than half of Windows users run Windows 8 or below.
------
Send a breaking news alert to Action News
Report a correction or typo
Want to comment?
Learn more about the 6abc apps