Your Windows 11 upgrade eligibility depends on far more than a single chip. While TPM 2.0 grabs all the headlines, millions of PCs are blocked by CPU generation limits, BIOS misconfigurations, insufficient storage, and firmware quirks that Microsoft’s own upgrade tool barely explains. This guide walks through every real hurdle โ and exactly what you can do about each one.
Why Windows 11 Compatibility Is Trickier Than Microsoft Lets On

When Microsoft launched Windows 11 in October 2021, it published a deceptively short list of minimum system requirements: a 1 GHz dual-core 64-bit processor, 4 GB of RAM, 64 GB of storage, a DirectX 12-compatible GPU, a 720p display, UEFI Secure Boot, and TPM 2.0. Simple on paper โ confusing in practice.
The PC Health Check tool flags many machines as incompatible without giving a clear reason. That is because there is not one gatekeeper; there are several, and they interact. Understanding each one separately is the only way to diagnose a blocked upgrade and decide whether to fix it, bypass it, or invest in new hardware.
The Full Windows 11 Requirements Checklist
Before you can upgrade to Windows 11, every item on this list must be satisfied:
- Processor: 1 GHz or faster, 2 cores minimum, 64-bit, on Microsoft’s approved CPU list (Intel 8th Gen+ or AMD Ryzen 2000+)
- RAM: 4 GB minimum (8 GB strongly recommended for day-to-day use)
- Storage: 64 GB free space on the system drive
- TPM: Trusted Platform Module version 2.0, enabled in firmware
- Firmware: UEFI with Secure Boot capability
- GPU: DirectX 12 compatible with a WDDM 2.0 driver
- Display: 720p, at least 9 inches diagonal, 8 bits per colour channel
- Internet: Required for initial setup on Windows 11 Home
Each item above can independently block an upgrade. Let’s break down the ones that cause the most confusion.
TPM 2.0: The Requirement Everyone Knows About

TPM 2.0 (Trusted Platform Module) is a dedicated security chip โ or a firmware-based equivalent โ that stores encryption keys and supports features like Windows Hello and BitLocker. It is built into virtually every CPU or motherboard made after 2016, but it is frequently disabled by default in BIOS/UEFI settings, which is why so many machines fail the check even when the hardware is present.
How to Check and Enable TPM 2.0
- Press Win + R, type
tpm.msc, and press Enter. - If the console shows “Compatible TPM cannot be found,” TPM is either disabled or not present.
- Restart your PC and enter BIOS/UEFI (usually Del, F2, or F10 at boot).
- Look for PTT (Intel Platform Trust Technology) or fTPM (AMD firmware TPM) and set it to Enabled.
- Save and reboot, then re-run
tpm.mscโ it should now report Version 2.0.
If your system genuinely has no TPM 2.0 support at all โ common on pre-2016 hardware โ you will need either a discrete TPM module (if your motherboard has a header for one) or a registry-based bypass for an in-place upgrade.
CPU Generation: The Hidden Windows 11 Compatibility Wall
This is the requirement that catches the most people off guard. Microsoft does not just require any dual-core 64-bit processor โ it requires a processor from its approved list. That list starts at Intel 8th Generation Core (Coffee Lake) and AMD Ryzen 2000 series. An Intel Core i7-7700K โ an excellent 2017 CPU โ is officially unsupported, even though it is technically capable of running Windows 11 without issue.
Checking Your CPU Generation
Press Win + Pause/Break or search “About your PC” in the Start menu. The processor model number tells you the generation: on Intel, the first one or two digits after the hyphen indicate the generation (e.g., i7-8700 = 8th Gen, i5-10400 = 10th Gen). On AMD, the first digit of the Ryzen number is the generation (Ryzen 5 3600 = 3rd Gen, which is supported).
If your CPU predates those cutoffs, the official upgrade path is blocked โ but Microsoft did release a registry workaround that bypasses both the TPM and CPU checks for an in-place upgrade. Note that doing so means your machine is unsupported, so you may not receive future feature updates.
BIOS vs UEFI: Secure Boot and Firmware Conflicts
Windows 11 requires UEFI firmware with Secure Boot, not the older Legacy BIOS mode. Many machines from 2012โ2018 have UEFI firmware but boot in Legacy/CSM mode with an MBR-partitioned drive, which blocks the upgrade entirely.
How to Switch to UEFI Without Reinstalling
- Open Disk Management and check whether your system disk uses MBR or GPT partitioning. GPT is required for UEFI boot.
- If your disk is MBR, use Microsoft’s built-in
mbr2gpt.exetool (run from an elevated command prompt) to convert it non-destructively before switching BIOS mode. - Then enter UEFI settings, disable CSM/Legacy mode, and enable Secure Boot.
- Reboot โ Windows 10 should still start normally, and the upgrade path to Windows 11 will now be clear.
Secure Boot conflicts are also common after adding a new GPU or storage controller. If Secure Boot was recently enabled and Windows fails to boot, hold Shift while clicking Restart to access the recovery environment and roll back the setting.
Storage: The 64 GB Floor and Why Speed Matters Too

The 64 GB storage requirement for Windows 11 compatibility is a hard floor, not a recommendation. The upgrade process itself needs roughly 20โ30 GB of temporary space on top of whatever the OS occupies, so a 64 GB drive that is 70% full will fail mid-upgrade and potentially leave your installation in an inconsistent state.
Beyond capacity, storage speed affects whether Windows 11 feels snappy or sluggish after the upgrade. Microsoft’s own testing indicates that machines running Windows 11 on a traditional spinning hard drive score significantly lower on the Windows Experience Index than those on an SSD. If your PC qualifies in every other way but runs on a mechanical drive, upgrading to a SATA or NVMe SSD is the single most impactful hardware change you can make โ the OS installation process itself becomes faster, and boot times can drop from over 60 seconds to under 15.
RAM: 4 GB Is the Limit, Not the Target
Windows 11 requires 4 GB of RAM to install, but that figure is misleading for assessing real Windows 11 upgrade eligibility. The OS itself uses roughly 2โ3 GB at idle, leaving almost nothing for open applications on a 4 GB system. For any practical workload โ a browser with a few tabs, a document editor, background antivirus scanning โ 8 GB is the realistic minimum, and 16 GB is comfortable for most users.
If your machine has 4 GB of DDR4 RAM and is otherwise compatible, check whether the memory is soldered or seated in upgradable DIMM slots. A RAM upgrade is often one of the cheapest ways to ensure the upgrade to Windows 11 actually delivers an improvement in day-to-day performance rather than just a new interface on a struggling system.
Running the PC Health Check โ and Reading the Results Properly
Microsoft’s free PC Health Check app gives a pass/fail result but rarely explains which specific requirement failed. Here is how to interpret its output:
- “The PC must support TPM 2.0” โ check BIOS for PTT/fTPM setting (see above).
- “The processor isn’t supported” โ CPU is below the 8th Gen Intel / Ryzen 2000 threshold.
- “The PC must support Secure Boot” โ firmware is in Legacy/CSM mode; convert disk to GPT and enable UEFI boot.
- “The PC doesn’t meet storage requirements” โ free up space on the system drive to at least 64 GB, ideally more.
For a more detailed diagnosis, download and run WhyNotWin11 โ a free open-source tool that checks each requirement individually and colour-codes the results, making it far easier to identify exactly what is blocking your upgrade.
What to Do If Your PC Fails Windows 11 Eligibility
If your hardware cannot be made compatible through BIOS tweaks alone, you have three realistic options:
- Use the registry bypass โ Microsoft’s official workaround disables the CPU and TPM checks for an in-place upgrade. The machine remains unsupported, and Microsoft warns that future updates are not guaranteed, but many users are running Windows 11 on older hardware without issue.
- Clean install via bootable USB โ a clean install from a Windows 11 ISO skips the Health Check entirely when you choose not to enter a product key during setup. You will need to activate Windows afterwards with a valid licence key.
- Upgrade the hardware โ if the machine is otherwise solid, a new motherboard and CPU may be more cost-effective than a full replacement, especially if RAM and storage can be reused.
Whichever route you take, you will need a valid Windows 11 licence to activate the installation. Buy Now Key offers genuine Windows 11 licences at competitive prices โ including Microsoft Windows 11 Home OEM from โฌ9.65 and Microsoft Windows 11 Pro OEM from โฌ12.90 โ so you can get the OS activated properly without overpaying.
Upgrade to Windows 11 Before Windows 10 Support Ends
Microsoft ends mainstream support for Windows 10 on 14 October 2025. After that date, Windows 10 machines will stop receiving free security patches, leaving them exposed to unpatched vulnerabilities. That deadline is the single biggest reason to resolve your Windows 11 compatibility issues now rather than later โ security updates are not optional for any internet-connected machine.
If your current machine passes the Windows 11 requirements checklist, the free upgrade from Windows 10 is still available via Windows Update as of mid-2025. If it does not pass, this guide gives you the tools to fix, bypass, or plan around every blocker on the list.
Frequently Asked Questions
Can I upgrade to Windows 11 if my CPU is not on Microsoft’s supported list?
Yes, but unofficially. Microsoft released a registry hack that bypasses both the CPU generation check and the TPM 2.0 requirement for an in-place upgrade from Windows 10. The resulting installation will not carry a “supported” status, which means Microsoft may exclude it from future feature updates โ though security patches have continued to reach these machines so far. Proceed with a full backup before attempting the bypass.
Does enabling TPM 2.0 in BIOS delete my data?
No. Toggling the TPM setting in UEFI firmware (enabling PTT on Intel or fTPM on AMD) does not erase your files, applications, or Windows installation. The only exception is if you already had BitLocker enabled and then clear the TPM โ in that case you would need your BitLocker recovery key to regain access. If BitLocker is off, enabling TPM is entirely safe.
What is the difference between UEFI and Legacy BIOS for Windows 11 requirements?
UEFI is a modern firmware interface that supports GPT disk partitioning, Secure Boot, and faster boot times. Legacy BIOS (also called CSM mode) is the older standard that uses MBR partitioning and does not support Secure Boot. Windows 11 requires UEFI with Secure Boot enabled. Many older PCs have UEFI firmware but are configured to boot in Legacy mode โ switching them to UEFI mode (after converting the disk from MBR to GPT) is usually sufficient to satisfy this requirement.
Will a clean install of Windows 11 skip the compatibility checks?
A clean install from a bootable Windows 11 USB drive does bypass the PC Health Check that runs during an in-place upgrade, but the installer still checks for TPM and Secure Boot by default. To skip those checks during a clean install, you need to add a specific registry key to the installer environment or use a modified ISO. Microsoft’s own documentation describes the registry method for in-place upgrades; for clean installs, the process is slightly different and involves editing the installer’s configuration before booting.
How do I know if my PC has enough free storage for the Windows 11 upgrade?
Open File Explorer, right-click your C: drive, and select Properties. You need at least 64 GB of total storage and enough free space for the upgrade process โ aim for at least 20โ30 GB of free space beyond your current OS footprint. If you are short, use the built-in Disk Cleanup tool or Storage Sense to remove temporary files, old Windows update caches, and the Windows.old folder from any previous upgrade before retrying.












