In a historic move, Microsoft will release the latest iteration of their Windows OS, Windows 10, as a free upgrade for existing users.

This removes at least one barrier to adoption among businesses, and it could be particularly advantageous for small to mid-size businesses (SMBs) by helping Microsoft stay competitive in the SMB space against Apple and Google who are ramping up their efforts for this audience.

The Windows 10 release signifies a shift in direction for Microsoft as its new leadership gains traction. However, it also brings many changes to the product itself.

Here’s what your SMB needs to know about the latest Windows release.

1. The upgrade has an expiration date

The official release date of Windows 10 has been listed as July 29, 2015. But, there’s so fine print. According to Gartner vice president Steve Kleynhans, it’s essential you do your research to determine if it is a good deal for your company within the timeline.

“Certainly it is nice getting the upgrade to Windows 10 for free, but it requires that you move in the next 12 months,” Kleynhans said.

2. Windows is now a service

Software upgrades used to be a major source of revenue for Microsoft in the past, but with Windows 10 comes a new model. Users will receive updates to the OS as time goes on.

“Windows 10 will be a ‘final’ upgrade that receives three to four upgrade packs a year that include new features,” said JP Gownder, a vice president and principal analyst with Forrester. “Windows as a service means you won’t be stuck with some 10 year old OS, as many were with XP, but it does require a little rethinking of resources, even these upgrade packs require some testing along the year.”

3. You have to be ready for the updates

As you consider whether or not to make the upgrade, it’s important to consider if you can handle the deluge of service packs that will come your way in this new system, Kleynhans said. You won’t have much time to “settle” into the new service packs before the next one comes.

“It will constantly be moving forward,” Kleynhans said. “You need to monitor it and test to see how it performs in your environment and decide when it is ready to fit into your environment.”

4. You can only upgrade from certain versions

To qualify for the Windows 10 upgrade, you must be upgrading from a Windows 7 or Windows 8.1 device. The availability of the upgrade for Windows Phone 8.1 varies by manufacturer, carrier, and operator. You’ll also need to have Windows Update enabled. Many of the enterprise versions are excluded from the upgrade offer, so make sure you check if yours is compatible.

5. There are different versions of Windows 10

Depending on your starting OS, you will get a comparable version of Windows 10 when you upgrade. Windows 7 Starter, Home Basic, Home Premium, and Windows 8.1 (4) will yield Windows 10 Home. Windows 7 Professional and Ultimate, and Windows 8.1 Pro and 8.1 Pro for Students will yield Windows 10 Pro.

6. Follow best practices for deployment

Just because Windows 10 is a new model for the OS doesn’t mean that it won’t come with some of the standard deployment pains you may have faced in the past. Make sure you time everything properly to minimize the number of problems you run into.

“OS upgrades, no matter how good, are disruptive,” Kleynhans said. “Don’t roll out Windows 10 right before your busiest selling season, or in the middle of implementing a new accounting system.”

7. Upgrade for security

Especially for SMBs, protecting your assets is critical. If you’re already a Windows shop, upgrading could bring some added security to your company.

“Security threats are only growing, and Windows 10 has some inherent application containerization that makes it more secure than its predecessors,” Gownder said.

8. It doesn’t (technically) require new hardware

While you will need a certain set of specs to run Windows 10 and a set amount of hard drive space, you probably won’t need to update your hardware. However, Kleynhans said, you might need new hardware to make use of new features such as Windows Hello or the advanced security. Unfortunately, he said, in may cases, that hardware won’t ship until later this year.

9. It’s a new user experience

One of the most contentious aspects of Windows 8 was its tile-based design. Some loved it, while others switched back to the standard desktop view immediately. Gownder said that Windows 10 is poised to provide the best of both tiles and the standard desktop, and will be optimized for mobile.

“If you have a detachable keyboard — say, on a Surface Pro 3 — the OS will default to desktop mode if the keyboard is attached, and to tile mode if it isn’t,” Gownder said. “So, it’s smart about desktop vs. mobile usage.”

10. The ecosystem might not be perfect

As we creep closer to the release date, it’s important to remember that although the OS might be ready, that doesn’t mean the ecosystem is. As an SMB, you might need additional support and, with the novelty of Windows 10, you might have trouble finding someone to provide the support right away, Kleynhans said.

Also, just because your key software or application works on Windows 10, that doesn’t always mean your vendor will provide Windows 10 support.

“They might need some time to complete some testing and make some tweaks,” Kleynhans said. “Talk to your software and service providers and understand their plans and timeline as your develop yours.”