Windows 10 to 11 upgrade keeps failing 48%

Talullah_2024 30 Reputation points
2025-08-08T15:56:42.1333333+00:00

I am using Windows 10 and have been trying to upgrade to Windows 11. Windows Assistant confirms my pc is compatible and I have checked the TPM.

Every time I download and run the upgrade it fails at 48% then rolls back the installation. I have tried it 3 or 4 times now and each time it fails at 48% despite try various fixes.

The errors I receive are generic. One time I had the error code 0xc1900101. another couple of times it was 'Invalid data access trap'.

I have looked extensively online and tried several 'fixes', including removing all peripherals such as external hard drives etc. I have disabled Bit Defender security.

I have plenty of disc space - 187GB used on a 500GB drive.

I am going to try again over the weekend and wondered if anyone can advise what I can do to resolve this?

Windows for home | Windows 11 | Install and upgrade
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Answer accepted by question author
DaveM121 937.5K Reputation points Independent Advisor
2025-08-08T16:32:09.73+00:00

The most successful method to upgrade to Windows 11 is to use the Windows 11 ISO.

Please ensure you download the ISO in the same language as you use for the Windows UI, follow the steps, this is then not like re-installing Windows, it is just like an update and your personal files, settings and installed software will not be affected.

Click this link:

https://www.microsoft.com/software-download/windows11

to download the Windows 11 ISO

When the ISO file completes downloading

Disconnect from the Internet

Disconnect all external devices with the exception of a mouse or keyboard.

Temporarily disable any 3rd party Anti-virus you may have installed

Then, in Windows File Explorer, double click the ISO and then run Setup.exe and select the Install option.

Very Important - ensure you select the option to keep your files and apps.

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  1. DaveM121 937.5K Reputation points Independent Advisor
    2025-08-08T17:10:21.7666667+00:00

    Yes, that is correct, on that web page, the 3rd (bottom) option can be used to download the ISO directly to your hard drive, no need for a USB.

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