{"id":75476,"date":"2024-06-10T19:13:33","date_gmt":"2024-06-10T13:43:33","guid":{"rendered":"http:\/\/198.58.113.91\/blog\/?p=75476"},"modified":"2024-06-10T19:15:10","modified_gmt":"2024-06-10T13:45:10","slug":"mbr2gpt-too-many-mbr-partitions","status":"publish","type":"post","link":"https:\/\/www.winhelponline.com\/blog\/mbr2gpt-too-many-mbr-partitions\/","title":{"rendered":"MBR2GPT | Too many MBR partitions found, no room to create EFI system partition"},"content":{"rendered":"<p>When you convert your MBR disk to GPT using MBR2GPT, the error &#8220;Too many MBR partitions found&#8221; may occur. Here&#8217;s the relevant info from the log:<\/p>\n<pre class=\"err\">Error     ValidateLayout: Too many MBR partitions found, no room to create EFI system partition.\nError     Disk layout validation failed for disk 2\n<\/pre>\n<p><!--more--><\/p>\n<p>This error occurs because there are already four primary partitions on that disk. MBR supports a maximum of four primary partitions. So, MBR2GPT cannot create the EFI partition.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-75478\" src=\"https:\/\/www.winhelponline.com\/blog\/wp-content\/uploads\/2024\/06\/diskmgmt-mbr2gpt-error.jpeg\" alt=\"mbr2gpt - too many MBR partitions\" width=\"1082\" height=\"139\" srcset=\"https:\/\/www.winhelponline.com\/blog\/wp-content\/uploads\/2024\/06\/diskmgmt-mbr2gpt-error.jpeg 1082w, https:\/\/www.winhelponline.com\/blog\/wp-content\/uploads\/2024\/06\/diskmgmt-mbr2gpt-error-768x99.jpeg 768w\" sizes=\"auto, (max-width: 1082px) 100vw, 1082px\" \/><\/p>\n<p>See also &#8220;Disk prerequisites&#8221; on this page:<\/p>\n<ul>\n<li>MBR2GPT | Microsoft Learn: <a title=\"learn.microsoft.com\" href=\"https:\/\/learn.microsoft.com\/en-us\/windows\/deployment\/mbr-to-gpt\" target=\"_blank\" rel=\"noopener noreferrer nofollow\">https:\/\/learn.microsoft.com\/en-us\/windows\/deployment\/mbr-to-gpt<\/a><\/li>\n<\/ul>\n<p>It states, &#8220;<em>Ensure that: There are at most three primary partitions in the MBR partition table.<\/em>&#8221;<\/p>\n<h2>Resolution<\/h2>\n<p>To resolve the issue, you need to delete one of the partitions. If that partition has important data, please back it up to a different partition beforehand. If you have multiple Recovery partitions, as in the screenshot above, the inactive Recovery partition can be deleted using the <em>diskpart<\/em> command-line.<\/p>\n<p>To determine which Recovery partition is used, run <strong>reagentc \/info<\/strong> in an admin Command Prompt in Windows. Note the disk # and partition #. The other partition can be deleted.<\/p>\n<p>You should now be able to convert to GPT using the MBR2GPT command. Here&#8217;s a sample MBR2GPT output after deleting one of the Recovery partitions:<\/p>\n<pre>C:\\WINDOWS\\system32&gt;mbr2gpt \/convert \/disk:2 \/allowfullos\n\nMBR2GPT will now attempt to convert disk 2.\nIf conversion is successful the disk can only be booted in GPT mode.\nThese changes cannot be undone!\n\nMBR2GPT: Attempting to convert disk 2\nMBR2GPT: Retrieving layout of disk\nMBR2GPT: Validating layout, disk sector size is: 512 bytes\nMBR2GPT: Trying to shrink the OS partition\nMBR2GPT: Creating the EFI system partition\nMBR2GPT: Installing the new boot files\nMBR2GPT: Performing the layout conversion\nMBR2GPT: Migrating default boot entry\nMBR2GPT: Adding recovery boot entry\nMBR2GPT: Fixing drive letter mapping\nMBR2GPT: Conversion completed successfully\nCall WinReReapir to repair WinRE\nMBR2GPT: Failed to update ReAgent.xml, please try to  manually disable and enable WinRE.\nMBR2GPT: Before the new system can boot properly you need to switch the firmware to boot to UEFI mode!\n<\/pre>\n<p>I hope that the above information helps.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>When you convert your MBR disk to GPT using MBR2GPT, the error &#8220;Too many MBR partitions found&#8221; may occur. Here&#8217;s the relevant info from the log: Error ValidateLayout: Too many MBR partitions found, no room to create EFI system partition. Error Disk layout validation failed for disk 2<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_feature_clip_id":0,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_post_was_ever_published":false},"categories":[8,869],"tags":[191],"class_list":["post-75476","post","type-post","status-publish","format-standard","hentry","category-windows-10","category-windows-11","tag-error-messages"],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack-related-posts":[{"id":75809,"url":"https:\/\/www.winhelponline.com\/blog\/mbr2gpt-cannot-find-os-partition\/","url_meta":{"origin":75476,"position":0},"title":"MBR2GPT | Cannot find OS partition(s)","author":"Ramesh","date":"July 3, 2024","format":false,"excerpt":"MBR2GPT.EXE is a built-in console tool that converts a disk from the Master Boot Record (MBR) to the GUID Partition Table (GPT) partition style without modifying or deleting data on the disk. When you run MBR2GPT to validate the disk before converting it to GPT, the following error may occur:\u2026","rel":"","context":"In &quot;Windows 10&quot;","block_context":{"text":"Windows 10","link":"https:\/\/www.winhelponline.com\/blog\/category\/microsoft\/windows\/windows-10\/"},"img":{"alt_text":"mbr2gpt- Cannot find OS partition","src":"https:\/\/i0.wp.com\/www.winhelponline.com\/blog\/wp-content\/uploads\/2024\/07\/mbr2gpt-validation-success.png?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.winhelponline.com\/blog\/wp-content\/uploads\/2024\/07\/mbr2gpt-validation-success.png?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/www.winhelponline.com\/blog\/wp-content\/uploads\/2024\/07\/mbr2gpt-validation-success.png?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/www.winhelponline.com\/blog\/wp-content\/uploads\/2024\/07\/mbr2gpt-validation-success.png?resize=700%2C400&ssl=1 2x"},"classes":[]},{"id":57345,"url":"https:\/\/www.winhelponline.com\/blog\/find-if-disk-is-mbr-or-gpt\/","url_meta":{"origin":75476,"position":1},"title":"How to Find if a Disk Uses MBR or GPT","author":"Ramesh","date":"July 1, 2023","format":false,"excerpt":"Knowing how your disks were set up (MBR vs. GPT) is essential for troubleshooting boot issues and Windows Update errors. Master Boot Record (MBR) disks use the standard BIOS partition table. GUID partition table (GPT) disks use the Unified Extensible Firmware Interface (UEFI). The boot files reside in the System\u2026","rel":"","context":"In &quot;Windows 10&quot;","block_context":{"text":"Windows 10","link":"https:\/\/www.winhelponline.com\/blog\/category\/microsoft\/windows\/windows-10\/"},"img":{"alt_text":"diskpart gpt disk or mbr","src":"https:\/\/i0.wp.com\/www.winhelponline.com\/blog\/wp-content\/uploads\/2023\/07\/diskpart-mbr-disk.png?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.winhelponline.com\/blog\/wp-content\/uploads\/2023\/07\/diskpart-mbr-disk.png?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/www.winhelponline.com\/blog\/wp-content\/uploads\/2023\/07\/diskpart-mbr-disk.png?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/www.winhelponline.com\/blog\/wp-content\/uploads\/2023\/07\/diskpart-mbr-disk.png?resize=700%2C400&ssl=1 2x"},"classes":[]},{"id":74926,"url":"https:\/\/www.winhelponline.com\/blog\/reagentc-exe-operation-failed-2\/","url_meta":{"origin":75476,"position":2},"title":"REAGENTC.EXE: Operation failed: Error 2 or Error 3bc3","author":"Ramesh","date":"April 24, 2024","format":false,"excerpt":"When you attempt to enable Windows RE by running the reagentc \/enable command, the following error may be shown: REAGENTC.EXE: Operation failed: 2 REAGENTC.EXE: An error has occurred. (or) REAGENTC.EXE: Operation failed: 3bc3 or REAGENTC.EXE: Unable to update Boot Configuration Data. The ReAgent.log may record the following error: Info [ReAgentc.exe]\u2026","rel":"","context":"In &quot;Windows 10&quot;","block_context":{"text":"Windows 10","link":"https:\/\/www.winhelponline.com\/blog\/category\/microsoft\/windows\/windows-10\/"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":74912,"url":"https:\/\/www.winhelponline.com\/blog\/bootrec-fixboot-access-is-denied\/","url_meta":{"origin":75476,"position":3},"title":"Error &#8220;Access is Denied&#8221; when running &#8220;Bootrec \/Fixboot&#8221;","author":"Ramesh","date":"April 23, 2024","format":false,"excerpt":"When you run the \"bootrec \/fixboot\" command from Windows RE, the error \"Access is denied\" occurs: Bootrec \/FixMbr -- writes the master boot record of the system partition using the master boot record compatible with Windows. This operation does not overwrite the existing partition table. Bootrec \/FixBoot -- write a\u2026","rel":"","context":"In &quot;Windows 10&quot;","block_context":{"text":"Windows 10","link":"https:\/\/www.winhelponline.com\/blog\/category\/microsoft\/windows\/windows-10\/"},"img":{"alt_text":"bootrec \/fixboot access denied","src":"https:\/\/i0.wp.com\/www.winhelponline.com\/blog\/wp-content\/uploads\/2024\/04\/fixboot-access-denied-gpt-uefi.png?resize=350%2C200&ssl=1","width":350,"height":200},"classes":[]},{"id":78024,"url":"https:\/\/www.winhelponline.com\/blog\/resize-efi-system-partition\/","url_meta":{"origin":75476,"position":4},"title":"How to Resize the EFI System Partition in Windows","author":"Ramesh","date":"March 5, 2025","format":false,"excerpt":"Summary: This post explains how to increase the size of the EFI partition to 250 MB without using any paid software. The EFI system partition stores the boot configuration database (BCD) and the boot files needed to boot a UEFI system. By default, the Windows setup creates a 100 MB\u2026","rel":"","context":"In &quot;Utilities&quot;","block_context":{"text":"Utilities","link":"https:\/\/www.winhelponline.com\/blog\/category\/utilities\/"},"img":{"alt_text":"resize efi partition using aomei free version","src":"https:\/\/i0.wp.com\/www.winhelponline.com\/blog\/wp-content\/uploads\/2025\/03\/resize_efi_9-3.png?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.winhelponline.com\/blog\/wp-content\/uploads\/2025\/03\/resize_efi_9-3.png?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/www.winhelponline.com\/blog\/wp-content\/uploads\/2025\/03\/resize_efi_9-3.png?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/www.winhelponline.com\/blog\/wp-content\/uploads\/2025\/03\/resize_efi_9-3.png?resize=700%2C400&ssl=1 2x"},"classes":[]},{"id":17918,"url":"https:\/\/www.winhelponline.com\/blog\/we-couldnt-update-system-reserved-partition-error-windows-10\/","url_meta":{"origin":75476,"position":5},"title":"[Fix] \u201cWe couldn\u2019t update system reserved partition\u201d Error updating Windows","author":"Ramesh","date":"August 16, 2020","format":false,"excerpt":"When upgrading to Windows 10 or 11 from Windows 7, 8, or 8.1, or updating Windows 10 or 11, you might encounter the error We couldn\u2019t update system reserved partition, or error 0xc1900104, or error code 0x800f0922. Update: If you're receiving the \"We couldn\u2019t update system reserved partition\u201d error or\u2026","rel":"","context":"In &quot;Windows&quot;","block_context":{"text":"Windows","link":"https:\/\/www.winhelponline.com\/blog\/category\/microsoft\/windows\/"},"img":{"alt_text":"We couldn\u2019t update system reserved partition","src":"https:\/\/i0.wp.com\/www.winhelponline.com\/blog\/wp-content\/uploads\/2020\/08\/system-reserved-partition-error-upgrade.png?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.winhelponline.com\/blog\/wp-content\/uploads\/2020\/08\/system-reserved-partition-error-upgrade.png?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/www.winhelponline.com\/blog\/wp-content\/uploads\/2020\/08\/system-reserved-partition-error-upgrade.png?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/www.winhelponline.com\/blog\/wp-content\/uploads\/2020\/08\/system-reserved-partition-error-upgrade.png?resize=700%2C400&ssl=1 2x"},"classes":[]}],"_links":{"self":[{"href":"https:\/\/www.winhelponline.com\/blog\/wp-json\/wp\/v2\/posts\/75476","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.winhelponline.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.winhelponline.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.winhelponline.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.winhelponline.com\/blog\/wp-json\/wp\/v2\/comments?post=75476"}],"version-history":[{"count":0,"href":"https:\/\/www.winhelponline.com\/blog\/wp-json\/wp\/v2\/posts\/75476\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.winhelponline.com\/blog\/wp-json\/wp\/v2\/media?parent=75476"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.winhelponline.com\/blog\/wp-json\/wp\/v2\/categories?post=75476"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.winhelponline.com\/blog\/wp-json\/wp\/v2\/tags?post=75476"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}