Microsoft is gearing up to release the second build of Windows 10 to almost all Lumia phones out in the market. The first build was rather limited, which was only allowed to be installed on six select Windows phones, namely Lumia 630, 635, 636, 638, 730 and 830. 

The limitations on the release of the Windows 10 Technical Preview stem from the partition size required to install the software. In a recent blog post, Microsoft revealed that the curb is now addressed with what it called "partition stitching," which allowed them to bring the build to several more handsets. 

The Redmond-based tech giant, however, left a caveat. At the moment, the company is validating individual phones. In the process, Microsoft will be pulling out a certain device from the list if a bug unique to a certain handset is spotted. 

Also, for those who wonder why their handset is not part of the list, it may be because a bug has already been detected on it. Microsoft emphasized that the bug "may" be eliminated in time for the next rollout of the build. 

The newer build of the operating system will likely be out next week although Microsoft has yet to determine a specific date. However, the tech firm has recently released the list of Lumia handsets that will be able to test the build.

Those who have their phones on the list and are interested to try the build should register their device in the Windows Insider program to receive the update over the air as they go. 

• Lumia 1020
• Lumia 1320
• Lumia 1520
• Lumia 520
• Lumia 525
• Lumia 526
• Lumia 530
• Lumia 530 Dual Sim
• Lumia 535
• Lumia 620
• Lumia 625
• Lumia 630
• Lumia 630 Dual Sim
• Lumia 635
• Lumia 636
• Lumia 638
• Lumia 720
• Lumia 730
• Lumia 730 Dual SIM
• Lumia 735
• Lumia 810
• Lumia 820
• Lumia 822
• Lumia 830
• Lumia 920
• Lumia 925
• Lumia 928
• Lumia ICON
• Microsoft Lumia 430
• Microsoft Lumia 435
• Microsoft Lumia 435 Dual SIM
• Microsoft Lumia 435 Dual SIM DTV
• Microsoft Lumia 532
• Microsoft Lumia 532 Dual SIM
• Microsoft Lumia 640 Dual SIM
• Microsoft Lumia 535 Dual SIM

Microsoft does warn users about the risks of trying out the technical preview, saying, "Don't say we didn't warn you... Technical Preview is for serious Windows Phone aficionados and tech experts. So if you think S/MIME has something to do with trying to escape an invisible box, you might want to stick with Windows Phone 8.1 for now."