Wednesday, September 3, 2025

How to Download and Install Windows 11 Complete Step-by-Step Guide

 









Intro: What this guide covers

This post shows every step you need to successfully install Windows 11 on a PC: checking compatibility, downloading the ISO, creating bootable media, BIOS/UEFI and TPM/Secure Boot settings, clean install and upgrade paths, common install errors and how to fix them, and recommended post-install tasks (drivers, updates, activation, backups).

Important: Installing or changing partitions will erase data. Back up all important files before you begin.

1) Minimum Windows 11 requirements (quick check)

Make sure your PC meets these (as of the commonly used Microsoft requirements):

  • 64-bit CPU, 1 GHz or faster, 2 or more cores (compatible 64-bit)

  • 4 GB RAM (recommended 8 GB+)

  • 64 GB or larger storage (SSD recommended)

  • UEFI firmware with Secure Boot capability

  • TPM 2.0 (or firmware TPM like Intel PTT / AMD fTPM)

  • DirectX 12 compatible graphics / WDDM 2.x

  • Internet + Microsoft account required for initial setup on Home editions

If a PC fails the compatibility check due to TPM/Secure Boot or CPU, later sections show safe options and troubleshooting.

2) Backups & preparation (DO THIS FIRST)

  1. Full backup: copy Documents, Pictures, Email, and license keys to an external drive or cloud.

  2. Export browser bookmarks and save any application license installers/keys.

  3. If BitLocker is enabled, suspend or decrypt it before changing partitions or OS.

    • Control Panel → BitLocker Drive Encryption → Suspend protection.

  4. Download essential drivers (network/Wi-Fi, storage) from your vendor and save to USB — handy if install media lacks them.

  5. Make note of product keys and Microsoft account credentials.

3) How to download Windows 11 ISO (official and safe)

You have two official routes:

Option A — Windows 11 Installation Assistant (in-place upgrade)

  • Best to upgrade from Windows 10 directly and keep files/apps.

  • Download from Microsoft’s Windows 11 download page → Windows 11 Installation Assistant → run and follow prompts.

Option B — Download ISO / Create USB (recommended for clean install)

  1. Visit Microsoft’s Windows 11 download page.

  2. Choose Download Windows 11 Disk Image (ISO).

  3. Select the edition & language, download ISO (usually multi-GB).

If you prefer the Media Creation Tool, Microsoft also offers tools that make USBs directly.

4) Create a bootable USB (two common methods)

Method A — Microsoft Media Creation Tool (easiest)

  1. Run the Media Creation Tool and choose Create installation media (USB flash drive).

  2. Insert an 8GB+ USB drive — the tool will format it and copy files.

Method B — Rufus (more options: bypass checks, GPT/UEFI settings)

  1. Download Rufus (portable).

  2. Open Rufus → Select your USB device.

  3. Click SELECT and choose the Windows 11 ISO.

  4. Choose Partition scheme:

    • GPT for UEFI (modern systems)

    • MBR Only if you must use Legacy BIOS (not recommended)

  5. Target system: UEFI (non CSM) for modern PCs.

  6. File system: FAT32 preferred for Secure Boot; Rufus can use NTFS with UEFI: NTFS if ISO >4GB.

  7. (Optional) Rufus has an “Extended Windows 11 installation” option to allow skipping PC health checks (TPM/SecureBoot) — only use if you fully understand the risk.

  8. Click Start, wait until complete.

Note: Creating USB will erase the drive.

5) BIOS/UEFI settings to check before install

Enter BIOS/UEFI (commonly F2, F10, DEL, ESC during POST) and ensure:

  • Boot mode: UEFI (disable Legacy/CSM)

  • Secure Boot: Enabled (if you plan an official install)

  • TPM / fTPM / Intel PTT: Enabled (look for “TPM Device”, “Security Chip”, “PTT”, “fTPM”)

  • SATA Mode: AHCI (recommended unless using RAID — then install RAID drivers)

  • Boot order: USB first (or use one-time boot menu F12)

  • Save & exit.

Vendor notes:

  • Dell: TPM — Security → TPM On; Secure Boot under Boot menu

  • HP: Security → TPM Embedded Security; Secure Boot in System Configuration

  • Lenovo: Security → TPM; Secure Boot under Security → Secure Boot

  • ASUS/MSI: look for TPM, fTPM, Security Device or PTT

6) Clean install vs Upgrade — choose your path

A — Clean install (recommended if you want a fresh OS)

  • Boot from USB → Choose Custom: Install Windows only (advanced) → delete old Windows partitions or format the target partition → install.

  • Pro: clean, fastest, fewer legacy issues. Con: must reinstall apps and restore files.

B — Upgrade / In-place (keep apps & files)

  • Run the Windows 11 installer from Windows 10 (or use Installation Assistant).

  • Choose Upgrade and follow prompts.

  • Pro: keeps apps and settings. Con: may carry over broken configs.

7) Step-by-step: Clean install procedure (detailed)

  1. Insert bootable USB and boot the PC (press F12/F11/F8 or set the USB first).

  2. On Windows Setup: choose language/time/keyboard → Next → Install Now.

  3. Enter product key or click I don’t have a product key if a digital license exists.

  4. Select edition (match license).

  5. Choose Custom: Install Windows only (advanced).

  6. Partitioning:

    • If the disk is fresh or you want a full clean:

      • Select the disk → click Delete on each partition until the disk shows Unallocated space (warning — destructive).

      • Click New to create partitions (Windows will create the required EFI and MSR partitions automatically).

    • If you must preserve other partitions, select the Windows partition and format it (not Delete) — still back up first.

  7. Select the partition and click Next — setup copies files & installs. PC will reboot automatically several times.

  8. Complete OOBE (out-of-box experience): choose region, keyboard, connect to network, sign-in with Microsoft account (or local account in Pro/Enterprise), privacy choices, PIN setup.

  9. After desktop loads: install drivers & Windows Update.

8) How to install if you get “This PC can’t run Windows 11” (TPM/Secure Boot/CPU warning)

Safe paths:

A — Enable TPM & Secure Boot in BIOS (preferred)

  • Reboot → BIOS → enable TPM (Intel PTT / fTPM) and Secure Boot → save and retry.

B — Use Rufus “Skip checks” mode (for unsupported hardware)

  • When making a USB with Rufus, choose a supported option (it offers choices to bypass TPM/Secure Boot checks). Use at your own risk — Microsoft doesn’t officially support these systems.

C — Registry bypass (not recommended except as a last resort)

  • If the installer blocks and you run setup from within Windows, you can create a registry key to bypass checks:

    1. On the error screen, press Shift+F10 → regedit

    2. Navigate to HKEY_LOCAL_MACHINE\SYSTEM\Setup

    3. Create key LabConfig and add DWORD values:

      BypassTPMCheck = 1
BypassRAMCheck = 1
BypassSecureBootCheck = 1
BypassStorageCheck = 1

    4. Close Regedit and retry setup.

  • Caution: bypassing makes you unsupported and could cause driver/security issues.

9) Common installation errors and fixes (complete list)

Error: “We couldn’t create a new partition / could not locate an existing partition”

Fixes:

  • Remove all external USB drives except the installation USB.

  • Use Diskpart to clean & convert to GPT (WARNING: erases disk):

# from setup use Shift+F10 -> cmd:
diskpart
list disk
select disk X   # X = target disk number
clean            # wipes disk
convert gpt
create partition primary
format fs=ntfs quick
assign letter=C
exit

Then retry installation.

  • For UEFI boot, ensure the disk is GPT. MBR can cause issues with UEFI Secure Boot.

Error: “0x80300024 / We couldn’t create a new partition at the selected location”

Fixes:

  • Use Diskpart clean as above.

  • If multiple disks, disconnect secondary drives during install.

Error: “Setup couldn’t find any drives / missing drivers”

Fixes:

  • This usually needs SATA or RAID drivers.

    • On another PC, download the storage/RAID driver (from the motherboard vendor) and place on USB, then in setup click Load driver and point to it.

  • Ensure SATA mode is AHCI (not RAID) if you don’t use RAID.

Error: Setup fails at x% and rolls back

Fixes:

  • Remove external devices.

  • Check installation media integrity (recreate USB).

  • If failing at the driver install stage, disconnect the NIC or remove non-essential hardware.

  • Try a clean install instead of an upgrade.

Error: “Product key can’t be used on this edition”

Fixes:

  • Ensure the chosen edition matches the product key (Home vs Pro).

  • Use a generic key to install and activate later with the proper key (or link Microsoft account digital license).

10) Installing on NVMe / RAID / Older SATA controllers

  • NVMe drives often need no extra driver on modern installs; if setup doesn’t detect NVMe, download the NVMe driver from the vendor and use Load driver.

  • For RAID arrays, ensure RAID drivers are loaded during setup.

11) After installation — immediate post-install checklist (do these first)

  1. Install the network driver if Windows didn’t do it — you’ll need internet for updates. (Have driver on USB.)

  2. Run Windows Update: Settings → Windows Update → Check for updates.

  3. Install chipset, graphics, and audio drivers from the vendor.

  4. Install virtualization drivers (if using Hyper-V, VMware Tools, VirtualBox Guest Additions).

  5. Reinstall/restore applications and data.

  6. Set up System Restore and create a system image (Control Panel → backup and restore).

  7. Enable BitLocker after ensuring TPM works and you have a recovery key backup (save to Microsoft account or external USB).

  8. Link the PC to your Microsoft account (Settings → Accounts) for digital license help.

  9. Configure privacy settings, default apps, and power plan.

12) Activation & Licensing

  • If you have a digital license linked to a Microsoft account, Windows 11 will auto-activate when online.

  • To enter a product key manually:

    • Settings → System → Activation → Change product key.

  • If activation fails, use phone activation or check the product key edition.

You can also use the command line:

# add a key
slmgr /ipk XXXXX-XXXXX-XXXXX-XXXXX-XXXXX

# activate
slmgr /ato

13) Dual-boot / keep Windows 10 alongside Windows 11

  • Shrink Windows 10 partition (Disk Management) to create space for Windows 11.

  • Boot from USB and install Windows 11 to a new partition (choose Custom install).

  • The boot menu (UEFI) will let you choose an OS. If not, use msconfig → Boot to manage.

14) Installing Windows 11 in a Virtual Machine

  • VirtualBox/VMware/Hyper-V supported. For VM settings:

    • Use UEFI & enable TPM (Hyper-V supports virtual TPM; VirtualBox 7+ has TPM options).

    • Assign 2+ CPU cores, 4GB+ RAM, and 64GB disk.

    • Mount Windows 11 ISO and boot.

15) Troubleshooting upgrade-specific problems (keep apps & files)

  • If upgrade fails:

    • Run sfc /scannow and DISM /Online /Cleanup-Image /RestoreHealth first.

    • Disable third-party antivirus and unplug external devices.

    • Clean up C:\Windows\SoftwareDistribution\Download and retry.

    • If stuck at “Working on updates”, let it run for 1–2 hours; otherwise, force a reboot and try in a clean boot.

16) If you need to roll back to the previous OS after the upgrade

  • Windows keeps the old installation for 10 days (by default).

  • Settings → System → Recovery → Go back (if available).

  • If it’s been more than 10 days or you deletedWindows.old, a data restore requires backup.

17) Performance & driver tuning after install

  • Install vendor drivers from the support site (not random driver sites).

  • Install chipset & storage drivers before heavy usage.

  • Run Windows Update several times to get driver & firmware updates.

  • Check Device Manager for unknown devices and resolve them.

18) Useful commands during trouble (copy/paste)

  • Check disk list / clean / convert to GPT:

diskpart
list disk
select disk 0
clean
convert gpt
create partition primary
format fs=ntfs quick
exit

  • Rebuild BCD / MBR fixes (from recovery command prompt):

bootrec /fixmbr
bootrec /fixboot
bootrec /scanos
bootrec /rebuildbcd

  • SFC & DISM:

sfc /scannow
DISM /Online /Cleanup-Image /RestoreHealth

19) Common post-install problems and fixes (short list)

  • No network after install: install the vendor NIC/Wi-Fi driver from USB.

  • Black screen after login: update graphics driver, use Safe Mode, restart Explorer.exe.

  • Sound not working: reinstall the audio driver or select the correct playback device.

  • Touchpad or hotkeys missing (laptops): install OEM hotkey and touchpad drivers.

20) Security tips & best practices after install

  • Enable BitLocker with TPM and back up recovery key.

  • Turn on Windows Defender and SmartScreen.

  • Enable Secure Boot (if you disabled it for install, and you can enable it).

  • Keep backups and create a system image.

21) Quick troubleshooting checklist (if install fails)

  1. Recreate the USB on a different USB stick and a different port.

  2. Ensure BIOS is set to UEFI and the disk is GPT.

  3. Enable TPM & Secure Boot if you want a supported install.

  4. Use Diskpart to clean the disk and convert it to GPT.

  5. Load missing drivers from the vendor USB when setup asks.

  6. Try an in-place upgrade (if clean fails) or vice-versa.

  7. If PC is unsupported and you must run Windows 11, use Rufus bypass, but understand you’ll be unsupported.

Final words

Installing Windows 11 can be straightforward when hardware meets requirements and you prepare drivers and backups in advance. For unsupported hardware, there are bypass options, but the safest route is enabling TPM & Secure Boot or using a supported PC. After installation, run Windows Update, install vendor drivers, create a system image, and enable security features.