Upgrade Windows Vista Home Premium OEM to Windows 8

Go to http://www.windows.com/buy

Clicking "Download Pro" installs and runs the Windows 8 Upgrade Assistant, which lets you know if your PC can upgrade to Windows 8 Pro, provides you with a compatibility report, and then walks you through the steps to purchase, download, and install. Run the Windows 8 Upgrade Assistant to make sure your PC can upgrade to Windows 8 Pro before purchase—you can run it without purchasing. Upgrade Assistant will collect certain information about your potential upgrade experience. Learn more about privacy and the Upgrade Assistant.

Step 1: Use the Upgrade Assistant to qualify the PC and pay the $40 (US)

Step 2: When the "Install Windows 8" message appears, select "Install by creating media" to create a bootable USB flash drive or an .iso (a disk image) file.

Step 3: Wait for the Assistant to download the Windows 8 Pro installation package and create the bootable media or .iso file. The flash drive must be have 3GB or more of free space available.

Step 4: Burn the .iso file, if that's the path you chose, to a blank DVD.

Step 5: Use that USB drive or DVD to boot the PC.

Step 6: When you get to the screen in Setup that asks, "Which type of installation do you want?' choose "Custom."

Step 7: Select a disk partition for the OS in the next screen. At this point, you can create a new partition if there's enough space available, or reformat the drive.

Step 8: Continue with the installation of Windows 8 Pro.