Windows 8.1 Upgrade Deletes VirtualBox Host-Only Network Adapter

<div><p>Windows 8.1 was released to the Windows Store last week and aside from having to download the same 3.9 GB update on each machine I've installed it on it's been a relatively easy and smooth update. I did, however, run into one small problem related to Oracle VirtualBox. When you install VirtualBox a "Host-Only" network adapter is installed in Windows to allow guest VMs to communicate with the Windows host, as the screenshot below shows:</p> <p><img alt="Network Connections Window" border="0" height="317" src="../../-_8-xK7b_9ak/UmbYUQczP5I/AAAAAAAACXQ/EGQy9CxH5m8/image-255B13-255D_imgmax-800.png" style="border-top: 0px; border-right: 0px; background-image: none; border-bottom: 0px; float: none; padding-top: 0px; padding-left: 0px; margin-left: auto; border-left: 0px; display: block; padding-right: 0px; margin-right: auto" title="Network Connections" width="579"/></p> <p>Unfortunately the Windows 8.1 upgrade process deletes the network adapter. After the upgrade you'll be faced with a warning message in the VM properties window and your VM won't start.</p> <p><img alt="VirtualBox VM Settings Window" border="0" height="495" src="../../-yk7sSh-YYJ8/UmbYU5srcKI/AAAAAAAACXY/SHZoeI1wIkU/image-255B14-255D_imgmax-800.png" style="border-top: 0px; border-right: 0px; background-image: none; border-bottom: 0px; float: none; padding-top: 0px; padding-left: 0px; margin-left: auto; border-left: 0px; display: block; padding-right: 0px; margin-right: auto" title="VirtualBox VM Settings" width="657"/></p> <p>The fix is easy - just reinstall VirtualBox. It's not a bad idea, actually, as at the same time as Windows 8.1 went live so did VirtualBox Version 4.3. The latest version has a few nice improvements that make it worth the upgrade, including: Multi-touch support, virtual USB webcam, a new NAT adapter that enables hosts and guests to communicate without requiring a host-only adapter, and the ability to record the entire VM session to video.</p> <p>As always, if you upgrade VirtualBox it's a good idea to upgrade the guest additions as well.</p> </div>