Microsoft's current preview of Windows Server 2016 is set to expire in just over a week, with no replacement due until May.
Windows Server Technical Preview was made available last October, but will stop working on April 15, with the next preview only scheduled for release at some point next month.
The Redmond giant said in a blog post that it will deliver an interim solution for customers wanting to continue using the preview, but with the expiry just eight days away, it may be a close run thing.
Exactly what improvements will be available in the second preview of Server 2016 are currently a mystery, but the preview was delayed from a slated January release to make room for significant changes.
This news broke shortly before a leaked Redmond presentation revealed Microsoft's working on a "Nano server" based on a Cloud OS infrastructure.
The virtualised nano server is aimed at letting IT admins deploy a lightweight server infrastructure, and the slides describe it as the "future nucleus" of Windows Server.
Whether or not Microsoft is far enough along the nano server track to make any of its features available in the latest Server 2016 preview remains to be seen, however.
The next iteration of Windows Server won't be released until next year, meaning it's not an option for those migrating from Server 2003, due to expire on 14 July 2015.
IT community Spicework's recent special report, The Great IT Upgrade, suggests that 48 per cent of 1,300 Server 2003 users are in the process of migrating, with 15 per cent already on another OS.
