Ask soldiers to list their mission-critical gear, and you might need to wait a bit until any of them mention their computer's operating system.

That doesn't make Windows any less important to the day-to-day duties of many soldiers and Army civilians, and it's why the upcoming Army-wide upgrade to Windows 10 – which will roll out in earnest in the coming weeks – should be on the radar of anyone who uses one of the 1.1 million-plus pieces of equipment that will feel the effects of the upgrade.

Here's 10 questions and answers about the changeover, straight from the office of the Army's Chief Information Officer/G-6 and Army Network Enterprise Technology Command.

1. How big a deal is this? "The Army is treating the Windows 10 rollout as a military operation," said Chief Warrant Officer 5 Brian S. Wimmer, a senior technical adviser with NETCOM, in a written response to Army Times questions on the move.

2. When does it happen? The Defense Department-mandated changeover to Windows 10, a move made to improve security and interoperability among military systems, is required by the end of January. The Army plans to "execute the transition as rapidly as feasible," officials said in the statement, but also plans to make use of a waiver process to allow more time for some systems.

3. Who goes first? The main rollout will come in a four-region approach. Soldiers in Europe are set to begin early this fall, with some test groups coming online in the next few weeks. They'll be followed by those in the U.S. and Southwest Asia, with the Pacific/Korea region rounding things out in early 2017.

4. What changes? Most of the upgrades will be under-the-hood security improvements, Army officials said. The user interface will be similar to Windows 7, with a familiar Start menu. But not every upgrade will be seamless.

5. How so? Not every legacy computer system will be compatible with Windows 10, which will create what officials called a "supportability challenge." And new security protocols may make it difficult for soldiers to download needed applications or files from external providers, at least until they can be marked as safe – or "whitelisted" – by the Army.

6. What about the new browser? Windows 10 comes with Microsoft Edge, which company officials laud as safer and faster than older versions. Unfortunately, some Army applications won't work with Edge if required plug-ins aren't compatible. Users facing such issues will need to switch to another browser, NETCOM said.

7. Do I really get to play Xbox games? No.

8. How come? Many so-called "universal applications" will show up as part of the Windows 10 Start menu, including an Xbox app and the popular Candy Crush Saga puzzle game. Those functions, and others outside the Army mission, are disabled on the Army's system, according to Col. Mark Orwat, chief of the CIO's installation and integration division.

9. What about all those PowerPoints? Relax – Office 2013 will remain on the new systems, featuring the same versions of Word, Excel and PowerPoint already in use.

10. What if I have questions or problems? A Windows 10 transition website will be live in the coming weeks, Orwat said, and a training schedule for tech professionals to get them up to speed on the upgrade is in the works. End users also will be able to access Windows 10 training via Army SkillPort, Orwat said. While the Army is tracking early adopters to see whether changes will be necessary to current tech-support pathways, Wimmer said indications are that "the service model will remain intact."