I recently had to do a reinstall of Windows 10 on a 3 year old Lenovo desktop. I previously updated the machine from Windows 7 to Windows 10, and shortly thereafter the hard drive started to give intermittent issues, so I decided to upgrade the machine with a SSD and do a clean install of Windows 10 at the same time. Turns out, installing Windows 10 from scratch isn’t that easy, so here are some of the things I discovered while researching the issue.
Do an In-Place Upgrade First!
This is just a friendly reminder, and not really relevant to any installation issues. But make sure that if you’re computer has not had Windows 10 installed previously, make sure to update the existing version first, even if you intend to do a clean install from scratch. The initial upgrade process registers your license with Microsoft, so that during the reinstall, you won’t have to enter any license keys. Also, during the upgrade process you can actually select to wipe the system, so you could do that and save yourself some trouble.
Making an Bootable USB Drive
Microsoft actually has a tool that you can download to build installation media for Windows 10. Download it from here: https://www.microsoft.com/en-us/software-download/windows10
Check Your BIOS Settings
Windows 10 (and Windows 8 for that matter) includes a lot of updates on how it interfaces with the most basic components on your machine. Foremost among these these is the support for UEFI BIOSes. UEFI replaces the old 16-bit BIOS standard with a new 64-bit standard. Most computers sold the last five years actually already run UEFI BIOS, but operate in “legacy mode”, aka. emulating the old 16-bit standard. For Windows 7 and older this was perfectly fine, but for newer Windows versions, especially Windows 10, you want to make sure that you enable UEFI mode or disable “legacy mode” in the BIOS settings. On some Lenovo models, this is called enabling “Legacy Free” mode.
Secondly, if you intend to run a SSD, you also want to check that your SATA controller is running in AHCI mode, not ATA (sometimes called IDE) mode. AHCI is a new standard for interfacing with disks, but some computers that ship with HDDs sometimes have this setting set to ATA, which basically means your SATA controller pretends to be an old-school IDE controller (remember those big flat cables?). Set this to AHCI to get the most out of your hard drives, especially SSDs.
Check that Your USB Stick is of the Right Kind
I’m assuming here that almost everybody that installs Windows 10 from scratch doesn’t own a DVD drive any more, and even you do, you probably don’t have any blank DVD-Rs handy.
This is single-handedly the thing that gave me the most grief. Windows 10 is for some odd reason really particular about the USB drive that you use. It doesn’t care what kind of stick you use, as long as it’s 4GB or larger. The problem comes when you plug the USB stick into the computer that you’re installing. Make sure that the USB drive you’re using is the same USB standard as the port on the computer! USB 3.0 drives needs to go into a 3.0 port and 2.0 drives into a 2.0 port. Or to keep it simple; blue drive – blue port, black drive – black port! I haven’t tested every possible combination, but I can at least verify that I had problems with a USB 3.0 drive in a USB 2.0 port. So, save yourself the headache, plug the drive into the right port.
Installing the Right Version of Windows
This is also important and relates to the licensing of upgraded versions of Windows. When you reinstall, you don’t need a license key if your computer previously ran Windows 10. But during the installation process, the installer is going to ask you which version you would like to install. Make sure to select the right version here (Pro or Home), and make sure that this is the actual version your computer is licensed for. The easiest way to check, if the machine came with an OEM license of and older version of Windows, is to examine the OEM license sticker on the computer chassis. If your computer came with Windows 7 Pro for example, and you updated that to Windows 10, it updated to Windows 10 Pro, and thus your computer is licensed for Windows 10 Pro.
That’s all the sticky points I found so far in the install process, I’ll add more here as I undoubtedly find them.