In Windows 10, especially Windows 10 Build 10158, Windows 10 Build 10159 and Windows 10 Build 10162, Windows 10 appears to use up all the gigabytes of free disk space on the HDD (hard disk drive) or SSD (solid state disk), leaving only several hundred megabytes of free disk space available, or worst, to totally run out of disk space.

The issue appears to be related to buggy Delivery Optimization (DoSvr) service, which performs content delivery optimization tasks when using peer-to-peer delivery of updates in Windows Update. The service erroneously writes meaningless log files repetitively to Windows log directory, which can adds up to hundreds of thousands files amounting to tens of GBs in disk space used.

To immediately reclaim the disk space, delete all files inside C:\Windows\Logs\dosvc folder.

To temporarily workaround the issue while waiting for Microsoft to fix the issue before Windows 10 gooes live, and so that Delivery Optimization service no longer generates any log files (and hence won’t fill up the disk space), disable the ‘Updates from more than one place’ option in Windows Update, which explicitly uses the Delivery Optimization service. This allows you to continue to receive updates from Microsoft, but not from other PCs via P2P method.

If you manually disable the Delivery Optimization (DoSvr) service without turning off the ‘Updates from more than one place’ option in Windows Update, Windows Update will fail to download and install any updates.