The release by Microsoft of a new Windows version is usually greeted with dread by lawyers and those who help administer their technology. Compatibility with existing software and hardware is the primary concern. Fortunately, the July 29 release of Windows 10 need not be feared.
Although Microsoft opted to skip the Windows 9 name and call its new operating system Windows 10, that is mostly marketing hype. They wanted distance from the not well-received Windows 8. In truth, when Windows 8 was updated to Windows 8.1, it became a decent, perhaps very good, operating system. In more truth, Windows 10 could just as easily been named Windows 8.2. The core of the operating system has not changed much. The key changes are in the user interface.
For that reason, if your hardware and software work with Windows 8.1, there is an overwhelming likelihood they will work with WIndows 10. That was the conclusion in this recent post on the always useful How-To Geek blog. That doesn't mean you should download and install this free upgrade on July 29, especially on your "mission critical" machines. Try it first on a spare machine, perhaps your home PC, to be sure everything works. Nothing says you have to be the first on your block with Windows 10. But if you are, there should be nothing to fear.