Would you believe that almost a year ago Microsoft released Windows 10 as a free upgrade? That means there's not a lot of time left if you've been avoiding the switch.

The last day to upgrade your computer running Windows 7 or Windows 8.1 to Windows 10 at no cost is July 29.

After that, you'll have to fork out $119 to buy a full version of Windows 10. You can also buy a whole new computer with the new OS pre-installed, but that costs quite a bit more.

Some quick tips to consider before beginning the upgrade process: Remember to back up your machine before you start.

Check to see if the programs you use most are compatible with Windows 10. And maybe write down your older Windows product key — just in case.