Refer to this thread : [INFORMATION] Windows 11 : Get Ready
Note : Once done, if you are looking to update directly from Windows 10 to Windows 11 without clean install, but that your hard drive is MBR and not GPT, you will need to convert it to GPT (without data loss) :- Right-click Windows Start button then click Search.
- Search for cmd. In the search results list, right-click Command Prompt and then click Run as administrator.
- If/When you are prompted by User Account Control, click Continue.
- At the command prompt, type mbr2gpt /validate /allowFullOS and press Enter.
- At the command prompt, type mbr2gpt /convert /allowFullOS and press Enter then once done close the Command Prompt then restart your PC.