Microsoft has pushed out the first batch of Windows 8.1 Preview updates through Windows Update less than a week after it was made available to the public. There are six updates in total, two of which are "important" while the other four are "recommended", and they address a range of things from virus definition updates for Windows Defender to fixing Windows Store apps that may crash upon launch.
The updates are available for both the x86/x64 Windows 8.1 Preview and the Windows RT 8.1 Preview, so you can now download them through Windows Update, found under the Updates & Recovery section of the PC Settings in the Preview. If you have updates set to automatically download and install, there isn"t much you"ll need to do to have the patches applied.
Source: CNET