How to install Windows 10

How to install Windows 10 Technical Preview as a virtual machine

Want to test-drive the new OS with the least amount of hassle? Give it a sandbox to play in.

Yep, that's Windows 10 running in a Windows 8, er, window.Photo by Rick Broida/CNET

Windows 10 has arrived! Well, an early beta, anyway, in the form of the Windows 10 Technical Preview. As noted in "Where, when and how to get Windows 10," Microsoft made the OS available for download as of last week.

Ready to take it for a spin? You have a couple options. If you have an old PC lying around, you couldinstall Windows 10 from a flash drive. But I think the better approach is to run the new OS inside a "sandbox," a virtual machine that won't affect your system in any way (except for borrowing some space on the hard drive).

Indeed, thanks to free virtualization software, you can run Windows 10 on your current PC -- then remove it when you've seen enough (or the Technical Preview expires, whichever comes first). The entire process takes about 30 minutes -- maybe longer depending on the speed of your PC. Here's how to make it happen:

Step 1: Start by downloading the Windows 10 Technical Preview ISO file. You'll need to click through the handful of "Get Started" and "Join Now" screens until you land at the download page, then scroll down and choose the appropriate language and version (32- or 64-bit).

Step 2: Download and install Oracle VM VirtualBox, the free virtualization tool that's going to make it possible for you to run Windows 10 inside Windows Whatever-You-Have.

Screenshot by Rick Broida/CNET

Step 3: Run VirtualBox, then click the New icon. In the Create Virtual Machine dialog box, type "Windows 10," then click the version selector and choose Windows 8.1 (making sure to match the ISO you downloaded: 32- or 64-bit). Then click Next.

Screenshot by Rick Broida/CNET

Step 4: VirtualBox will show a recommended memory size; go ahead and accept unless you have a specific reason for changing it. Then select "Create a virtual hard drive" and click Create. Accept VDI (VirtualBox Disk Image) as the file type for the drive, then choose Fixed Size for the virtual drive. Finally, click Create, then wait while VirtualBox builds your virtual drive.

Screenshot by Rick Broida/CNET

Step 5: Once the drive is ready, click the Start button in the VirtualBox toolbar. You'll see a box telling you to "Select start-up disk." Click the little file folder next to the pull-down, then navigate to the Windows 10 ISO file you downloaded in Step 1. Then, click Start -- you're off to the races!

Screenshot by Rick Broida/CNET

Step 6: Install Windows as you normally would, making sure to choose the "Custom: Install Windows only (advanced)" option when it presents itself. As usual, the setup process may involve a few reboots, though only within the confines of the virtual machine.

And that's it! When it's all done, you should have Windows 10 running in a window. However, one thing I've discovered -- at least following my two deployments -- is that the new Start Menu doesn't appear right away. Although installation appears to be complete, you have to reboot -- manually -- one more time.