So far, so good… mostly. All my files and settings made it over just fine, even including saved logins for websites in my various browsers (Internet Explorer, Chrome, Firefox, Opera). There doesn’t seem to be any compatibility problems with accounting or office software. I had Quickbooks 2011 already installed during the upgrade, and it passed through without issue. I installed Sage 2013 afterwards, and likewise no issue. An older version of Libreoffice (126.96.36.199) also survived the upgrade just fine, as did Office 2013, as expected. This site has a chart that is a good reference for Windows/Office compatibility and support dates, up until Windows 8.1/Office 2013:
I haven’t heard any significant complaints of older versions of Office not working on Windows 10, but I wouldn’t recommend using Office 2003, as it is no longer being supported, even if it works.
I’ve seen a few window glitches since the upgrade, such as a window beneath showing through the top window, or clicking in a menu in a full screen game and having it click and launch the taskbar app in that spot… occasional annoyances like that, but no show-stoppers. Some games had to be run in compatibility mode or run as an administrator, but otherwise with games, if it ran in Windows 8, it runs in Windows 10.
The most annoying change for me was the new multiple monitor handling: you have to drag the windows quickly, or it will want to “snap” them to the edge of the screen rather than move them to the desired screen (you can change this behavior under Settings->System->Multitasking->Snap). Another annoyance is the forced updates. This by and large is a good thing moving forward, but when it comes to drivers, newer isn’t always better… some Nvidia graphics card users kept getting forced a non-working driver. There is a update blocker tool available from Microsoft, but it only works with the “Pro” edition of Windows, not “Home”.
Of course, what discussion of the upgrade of Windows 8 to 10 would be complete without mention of the return of the start menu? Yes, it’s back. But, it’s replaced many of the Windows 7 entries with their Windows 8 alternatives. For example, instead of “Control Panel” you have “PC settings” with functionality divided up between the pages differently compared to Windows 7 and prior. The default behavior had me clicking a lot more to get to the places I wanted to go to, like “My Documents”. If I wanted to type a search to go right to a program, if it was an administrative utility, I had to type out the full file name exactly, otherwise it would just do a web search… Mind you, most of you reading this don’t use admin utilities day-to-day, but I would be remiss to not mention it. To be honest, it you lived off of the start menu in the past, you’ll still be better off installing Classic Shell to get that Windows 7 feel.
There is built-in voice search called “Cortana”. Assuming you have a microphone, you click the mic button on the search bar and say “Hey Cortana…” and then make your query. Comparing to Google’s and Apple’s voice assistants, accuracy is all in the same ballpark. Where Cortana moves a bit ahead of Google’s all-business assistant, and is a bit more like Apple’s Siri, is in the banter. If you ask Google’s assistant to tell you a joke, it will bring up a search result page. You ask Cortana or Siri the same, they will tell you a random joke. If you ask Cortana or Siri about their competitor, they will give you a witty comment.
All considered, if you have Windows 7, on a desktop, and like the way things are now, stay with it for remaining useful life of the computer (although upgrade to an SSD if you haven’t yet). Windows 8 and 10 brought some power-use improvements, so laptops running Windows 7 have some incentive to go straight to Windows 10. Anyone running Windows 8, though, will find Windows 10 a clear and simple upgrade. Its stability and compatibility is plenty good for the vast majority at this point.
Lastly, you have one month after the upgrade to roll back to the previous Windows if you don’t like it. After a month it will delete the old windows files (not your personal files). It will then be licensed to that machine for good, as a Windows 10 license. Even if you keep the Product Key sticker and the Windows 7 disc, for example, that license is now no longer valid as Windows 7, but as Windows 10.