The upgrade is free for one year, so if you haven't yet installed it, you have plenty of time to decide whether or not to dive in. On Wednesday, Microsoft officially started pushing out Windows 10 as a free upgrade to Windows 7 and 8.1 users who reserved a copy. Microsoft has rolled out a free evaluation version of Windows 10 Enterprise edition so you can play with it for 90 days if you're still on the fence about upgrading. You can test-drive the free Windows 10 Enterprise edition for 90 days, though it is missing many key Windows 10 apps.
