Windows Phone 7 updates need to be completed through official channels, Microsoft says.

If you updated your Windows Phone 7 device outside of Microsoft's official channels, you won't be able to use the mobile platform's latest version.

That's according to Microsoft's Brandon Watson, who wrote about the issue on the company's developer blog yesterday. Anyone who updated their Windows Phone 7 devices to build 7390 via "unofficial mechanisms" will be unable to complete the update to the company's latest build, 7392, he wrote.

"Despite the fact that many people have claimed that an unofficial update mechanism worked fine for them, we cautioned that phones which were updated via this method were not going to be able to update past build 7390," wrote Watson, a senior director for Windows Phone. "Unfortunately for those customers out there who acted on information from sources outside of Microsoft, the rubber meets the road today."

Microsoft's 7392 build is what the company calls a "small new update." Rather than add new features to the device, the update addresses "nine fraudulent third-party digital certificates." Microsoft started rolling out the update this week.

The fact that some folks have turned to "unofficial" updates for Windows Phone 7 isn't all that surprising. Back in February, Microsoft attempted to update Samsung's Omnia 7 phones, but before long, some of the updated devices were bricked due to issues in the update. Microsoft then pulled the update to address bugs and tried again. Once again, it caused problems. Since then, the company has come under fire for its update process, leading Microsoft Corporate Vice President Joe Belfiore last month to admit that his company suffered from a "lack of preparation."

But it seems Microsoft didn't learn its lesson. Last week, the company started distributing an update to Samsung Omnia 7 devices, only to be forced to once again stop the update process due to a "technical issue." Microsoft hopes to restart the update process soon.

Microsoft said that when the latest update is applied to unofficially updated smartphones, owners will get an 80180048 error code. Microsoft said that those who receive the error code will "most likely have to return to a store and submit your phone for a manufacturing return" to address the problem.

Luckily for those folks, third-party providers who created the unsupported tools are working on a fix to "get these phones back on the officially supported path." Microsoft said that it won't be working on a fix itself, but it will work with the third-parties to "validate their solution."

Until that happens, however, those who went through unofficial channels to update their devices seem to be out of luck.

"I personally feel really bad for customers who find themselves with phones which are now stuck," Watson said.