The problem with upgrading to a new version of Windows isn’t so much the new version of the operating system itself — it’s whether the applications and devices you need to use in your business will be compatible with the new release.

Historically, that’s been painful for large organisations with thousands of applications, internally written and from third parties, or with peripherals that are still working but no longer supported with updated drivers. Memories of past pain can make IT departments wary of upgrades, either because of the problems they expect or the time and the resources they spend testing applications to make sure they’re compatible — even with tools like the Office Readiness Toolkit and Upgrade Readiness in Windows Analytics.

Over and over again, customers told Microsoft that worries about app compatibility were stopping them upgrading to Windows 10 or keeping up with the twice-yearly feature updates. And with less than a year until Windows 7 is out of extended support, that’s a problem.

Windows already has compatibility mechanisms to make applications run that worked with older releases. Windows 10 ships with thousands of compatibility ‘shims‘ for specific applications. According to Bernado Caldas, general manager of the Windows Commercial team at Microsoft, extensive analytics shows that more than 99 percent of applications are compatible with Windows 10, and 99 percent of commercial third-party add-ons and plug-ins are compatible with Office 365 Pro Plus.

“Less than 0.3 percent of documents could have potential macro issues, but that could be a critical issue for our financial services customers who have a lot of spreadsheets with macros. So we’ve done a lot of compatibility work for that. There’s a set of 64-bit documents with macros that might need remediation. That’s less than one percent — we estimate it’s as low as 0.6 percent.”

Microsoft has always worked with large organisations to fix specific problems, but some customers simply wouldn’t expect to get that level of help — so it made the process less ad hoc and more systematic.

With Desktop App Assure, customers just send a request through the FastTrack portal and Microsoft assigns an engineer who works with them until the issue is fixed — whether that means helping them change their own code, getting an OEM to make changes or even changing things in Office or Windows to solve it.

We break it, we fix it

Some customers expected this to work the way a consulting engagement would, with Microsoft coming in and auditing the applications they use. Instead, explains Aleks Lopez, who runs the Desktop App Assure team, it’s a ‘break-fix’ service to use when an app doesn’t work on Windows 10. Others just wanted to know if Microsoft was really looking at the requests.

“A lot of customers think we’re not really a person that will pick up a phone and help them. When they submit a request and realise that there are people here who will work with them at no cost, they tell us that they don’t have an issue right now but they’re glad to know we’re here and they’ll use the service once they start upgrading.” In the end, few if any of those customers looking for the assurance that the service is real end up coming back with issues — but Lopez wouldn’t want them not to make that first call.

“Even something that’s simple to us, customers don’t have the right visibility. They think it’s going to be a huge problem and it will be super difficult. Even if it’s not a lot of applications, even if it’s only a handful of problems, it’s really stressful. For us, it’s a simple fix that we’ve seen a million times and it’s easy to resolve. For them it was difficult, and it created a lot of anxiety.”

The first wave of Desktop App Assure requests covered some 7,000 applications (out of 41,000 that the customers asking for help were using). Of those 7,000 apps, only 49 needed any fixes. That’s 0.7 percent of the applications that worried customers, so the team started tracking how many of their applications customers expected would have issues. “They think 17 percent of their applications will break, and what we’re seeing overall is it’s 0.12 percent,” Lopez told TechRepublic.

That’s what the Windows team always expected, “but you never know how many customers have old versions of Windows and what’s out in the line-of-business ecosystem behind a firewall that we don’t get telemetry signals from,” said Lopez. That uncertainty led Microsoft to put a significant number of people on the Desktop App Assure team: “the volume [of requests] is significantly lower — a fraction of what we anticipated,” Lopez added.

The most common problem is customers who are moving to Windows 10 to improve security discovering issues in applications. But the issues aren’t necessarily new to Windows 10, Lopez notes. “Yes, the OS itself is more secure, but often they deployed Windows 7 over ten years ago and they didn’t opt-in to security features like UAC [User Account Control] that they’re opting into now. Lots of customers no longer want to allow apps to run in admin mode. They’re opting into more features that were there in Windows 7, and it breaks those applications on Windows 10 as well.”

SEE: System update policy template download (Tech Pro Research)

For one un-named ‘global IT services consulting firm’, the problem was the SetWindowsHookExA function in the USERS32.DLL Windows library their application was using to query values from an Access 2003 database. The app had worked on Windows 7 with UAC disabled, but with UAC on it wouldn’t let users select or update data on either Windows 7 or Windows 10 — and they didn’t have the source code.

Other common problems are as basic as the customer not having upgraded to a new version of their application that’s compatible with Windows 10, because they didn’t know there was one. In fact, so many of the Desktop App Assure reports were getting fixed by the team searching on the web for the application upgrade details that Microsoft app compatibility expert Chris Jackson wrote a blog with tips on how to search yourself.

A lot of Desktop App Assure requests are about support statements from software vendors; the software might work perfectly well on Windows 10, but if the software vendor hasn’t committed to supporting it on future releases of Windows 10, customers are worried they’ll be running it without support. In those cases, says Lopez, “We reach out to the software vendor to show them how they can get support from us, and that typically gives them the confidence to issue a support statement.”

Sometimes it’s the software vendor asking for help with problems their customers have when upgrading. Single sign-on to WinMagic SecureDoc full disk encryption used to stop working after a Windows 10 update because a registry key was getting deleted during the upgrade. The Windows team was able to find the problem and develop a fix that migrated the full set of registry keys during an update in two weeks. Instead of asking customers to wait while they test new releases, WinMagic now guarantees that SecureDoc will be compatible with all new Windows 10 updates within 30 days — and eventually that compatibility will be guaranteed on the day Windows updates are released.

No source code, no problem

Those 0.12 percent of apps that have a problem tend to be older applications. “We are seeing customers who have apps that were built in 1995 and the developer is long gone,” Lopez says. “The app ran on Windows 7, they move to Windows 10 and some failure occurred.” Problem apps have included Access 2003, Visual Basic 5 and Visual Basic 6 applications. Sometimes it’s turning on security features that causes the problems; other times there are references to APIs that have been deprecated.

If there’s a developer in the organization that can update the source code, the Desktop App Assure team will help them to do that. If not, Microsoft can create a shim for the application to get it running again. For the consultants who had the failing Access 2003 app and no source code, the team created a shim, Authenticode-signed the executable and changed the installation folder so it ran from a trusted location, which solved the problem.

One customer had a 32-bit application, which Microsoft knew would run on a 64-bit version of Windows without any problems. But it was packaged with a 16-bit installer that wouldn’t run, so the Desktop App Assure team helped them create a Windows 10 package to install it.

And sometimes it turns out to be a problem in Windows, which Microsoft then fixes (and Desktop App Assure fixes get priority from the Windows and Office teams). It’s rare for the problem to be in Windows though, and when it is it’s usually an edge case with a unique combination of technologies and applications rather than a bug that will affect a lot of users, Lopez says. “Whenever we’re making a fix in the OS, it’s typically isolated to a specific software vendor or customer, or at most a handful of customers, not a large number of organizations.”

Hendrick Automotive Group, a large US car dealership, had one of those rare combinations. “There was an old printer in some of their offices that worked with their line-of-business app that just wasn’t compatible and did require remediation,” says Caldas. “We fixed it with a single line of code.”

SEE: 20 pro tips to make Windows 10 work the way you want (free PDF) (TechRepublic)

It wasn’t fear that sent Hendrick to Microsoft, VP for Information Technology Robert Taylor told TechRepublic: “It was just truly the unknown, and we wanted to do it right from the beginning.”

Hendrick’s IT team has 52 people to look after 10,000 staff at nearly 130 dealerships and service centres across the US, which in turn handle 27 different car brands like BMW, Chevy, Fiat, Honda and Porsche. That means running tools from 27 different OEMs that they have no control over, including the programming stations used for car keys that run apps that call back to the car-maker’s system — which might be in Japan or Germany. Some of those needed changes, which Microsoft co-ordinated with the manufacturers.

Upgrading the Windows PCs to which payment processing terminals connect involved what Taylor understatedly calls ‘some nuances’. It didn’t help that entire dealerships have to be upgraded overnight, between 10pm and 6am (or on a Sunday, for larger locations). “The process by which terminals had to be removed from inventory and deprovisioned, have the software removed, the new OS and then the software installed and then have the payment terminal re-registered — Microsoft actually brought people on site to script that,” Taylor said.

Even if you don’t need that level of support, Taylor encourages other businesses to use Desktop App Assure. “What most technology departments struggle with is asking for help from someone who knows more about the tech,” he notes.

Hendrick is halfway through its Windows 10 migration, and the compatibility support it has received from Microsoft means the IT team feels comfortable about keeping Windows up to date in future — which is exactly what the program is designed to do.