Following today's release of the Windows 10 January Technical Preview, Microsoft has issued an Update Rollup. The Rollup fixes a number of issues in today's release, and requires you to be running that release in order to install.
Issues addressed in the Rollup include reliability, with a new fix that will prevent some system crashes in the Explorer, as well as improvements in live migrations of virtual machines. Also fixed is an issue that could cause deleted apps to be reinstalled, and power efficiency has been improved.
Internet Explorer now performs better, and an issue that caused pending Windows Updates to be incorrectly reported in the update history has also been removed. The Rollup also fixes an issue that caused the Start Menu to fail to launch, as well as one that could cause pixilation on the screen when using Remote Desktop Client.
In order to install the Rollup, you must be running Windows 10 Technical Preview build 9926, today's release.