diff --git a/web/__test__/components/UpdateOsDowngrade.test.ts b/web/__test__/components/UpdateOsDowngrade.test.ts
new file mode 100644
index 0000000000..02f252506d
--- /dev/null
+++ b/web/__test__/components/UpdateOsDowngrade.test.ts
@@ -0,0 +1,127 @@
+import { mount } from '@vue/test-utils';
+
+import { beforeEach, describe, expect, it, vi } from 'vitest';
+
+import UpdateOsDowngrade from '~/components/UpdateOs/Downgrade.vue';
+import { createTestI18n } from '../utils/i18n';
+
+const mockViewReleaseNotes = vi.fn();
+const mockServerStore = {
+  bootedFromFlashWithInternalBootSetup: false,
+  dateTimeFormat: { date: '%A, %m/%d/%Y', time: '%R' },
+  osVersion: '7.3.0',
+};
+
+vi.mock('pinia', async (importOriginal) => {
+  const actual = (await importOriginal()) as typeof import('pinia');
+  return {
+    ...actual,
+    storeToRefs: (store: Record<string, unknown>) =>
+      Object.fromEntries(
+        Object.keys(store).map((key) => [
+          key,
+          {
+            get value() {
+              return store[key];
+            },
+            set value(value: unknown) {
+              store[key] = value;
+            },
+          },
+        ])
+      ),
+  };
+});
+
+vi.mock('@unraid/ui', () => ({
+  BrandButton: {
+    template:
+      '<button :data-button-name="name" :data-button-text="text" @click="$emit(\'click\')">{{ text }}</button>',
+    emits: ['click'],
+    props: ['name', 'text'],
+  },
+  CardWrapper: {
+    template: '<div><slot /></div>',
+  },
+}));
+
+vi.mock('~/helpers/urls', async (importOriginal) => {
+  const actual = await importOriginal<typeof import('~/helpers/urls')>();
+  return {
+    ...actual,
+    FORUMS_BUG_REPORT: new URL('https://example.com/bug-report'),
+  };
+});
+
+vi.mock('~/store/server', () => ({
+  useServerStore: () => mockServerStore,
+}));
+
+vi.mock('~/store/updateOsActions', () => ({
+  useUpdateOsActionsStore: () => ({
+    viewReleaseNotes: mockViewReleaseNotes,
+  }),
+}));
+
+describe('UpdateOs/Downgrade', () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+    mockServerStore.bootedFromFlashWithInternalBootSetup = false;
+    mockServerStore.dateTimeFormat = { date: '%A, %m/%d/%Y', time: '%R' };
+    mockServerStore.osVersion = '7.3.0';
+    (window as Window & { confirmDowngrade?: () => void }).confirmDowngrade = vi.fn();
+  });
+
+  const mountComponent = (version = '7.2.5') =>
+    mount(UpdateOsDowngrade, {
+      props: {
+        releaseDate: '2024-01-01',
+        version,
+      },
+      global: {
+        plugins: [createTestI18n()],
+      },
+    });
+
+  it('starts downgrade immediately when warning conditions are not met', async () => {
+    mockServerStore.osVersion = '7.2.9';
+    mockServerStore.bootedFromFlashWithInternalBootSetup = true;
+
+    const confirmSpy = vi.spyOn(window, 'confirm').mockReturnValue(true);
+    const wrapper = mountComponent('7.2.8');
+
+    await wrapper.find('[data-button-name="downgrade"]').trigger('click');
+
+    expect(confirmSpy).not.toHaveBeenCalled();
+    expect(window.confirmDowngrade).toHaveBeenCalledTimes(1);
+    expect(wrapper.text()).not.toContain('Internal boot downgrade risk');
+  });
+
+  it('shows warning and blocks downgrade when user cancels confirmation', async () => {
+    mockServerStore.osVersion = '7.3.0-beta.2';
+    mockServerStore.bootedFromFlashWithInternalBootSetup = true;
+
+    const confirmSpy = vi.spyOn(window, 'confirm').mockReturnValue(false);
+    const wrapper = mountComponent('7.2.3');
+
+    await wrapper.find('[data-button-name="downgrade"]').trigger('click');
+
+    expect(confirmSpy).toHaveBeenCalledTimes(1);
+    expect(window.confirmDowngrade).not.toHaveBeenCalled();
+    expect(wrapper.text()).toContain('Internal boot downgrade risk');
+  });
+
+  it('shows warning and allows downgrade after explicit confirmation', async () => {
+    mockServerStore.osVersion = '7.3.1';
+    mockServerStore.bootedFromFlashWithInternalBootSetup = true;
+
+    const confirmSpy = vi.spyOn(window, 'confirm').mockReturnValue(true);
+    const wrapper = mountComponent('7.1.0');
+
+    await wrapper.find('[data-button-name="downgrade"]').trigger('click');
+
+    expect(confirmSpy).toHaveBeenCalledTimes(1);
+    expect(window.confirmDowngrade).toHaveBeenCalledTimes(1);
+    expect(wrapper.text()).toContain('Internal boot downgrade risk');
+  });
+});
diff --git a/web/src/components/UpdateOs/Downgrade.vue b/web/src/components/UpdateOs/Downgrade.vue
index 7a1a3b32c6..3a65fc97ce 100644
--- a/web/src/components/UpdateOs/Downgrade.vue
+++ b/web/src/components/UpdateOs/Downgrade.vue
@@ -1,5 +1,5 @@
 <script lang="ts" setup>
-import { ref } from 'vue';
+import { computed, ref } from 'vue';
 import { useI18n } from 'vue-i18n';
 import { storeToRefs } from 'pinia';
 
@@ -13,6 +13,8 @@ import {
 import { BrandButton, CardWrapper } from '@unraid/ui';
 import { FORUMS_BUG_REPORT } from '~/helpers/urls';
 import dayjs from 'dayjs';
+import coerce from 'semver/functions/coerce';
+import lt from 'semver/functions/lt';
 
 import type { UserProfileLink } from '~/types/userProfile';
 
@@ -29,7 +31,7 @@ const { t } = useI18n();
 const serverStore = useServerStore();
 const updateOsActionsStore = useUpdateOsActionsStore();
 
-const { dateTimeFormat } = storeToRefs(serverStore);
+const { bootedFromFlashWithInternalBootSetup, dateTimeFormat, osVersion } = storeToRefs(serverStore);
 const { outputDateTimeFormatted: formattedReleaseDate } = useDateTimeHelper(
   dateTimeFormat.value,
   t,
@@ -37,6 +39,43 @@ const { outputDateTimeFormatted: formattedReleaseDate } = useDateTimeHelper(
   dayjs(props.releaseDate, 'YYYY-MM-DD').valueOf()
 );
 
+const INTERNAL_BOOT_SUPPORT_VERSION = '7.3.0';
+
+const isVersionIn73Series = (version: string | null | undefined) => {
+  const normalizedVersion = coerce(version);
+  if (!normalizedVersion) {
+    return false;
+  }
+  return normalizedVersion.major === 7 && normalizedVersion.minor === 3;
+};
+
+const isBeforeInternalBootSupportVersion = (version: string | null | undefined) => {
+  const normalizedVersion = coerce(version);
+  if (!normalizedVersion) {
+    return false;
+  }
+  return lt(normalizedVersion, INTERNAL_BOOT_SUPPORT_VERSION);
+};
+
+const shouldWarnAboutInternalBootDowngrade = computed(
+  () =>
+    bootedFromFlashWithInternalBootSetup.value &&
+    isVersionIn73Series(osVersion.value) &&
+    isBeforeInternalBootSupportVersion(props.version)
+);
+
+const startDowngrade = () => {
+  if (shouldWarnAboutInternalBootDowngrade.value) {
+    const confirmed = window.confirm(
+      t('updateOs.downgrade.internalBootConfirmFrom73xToOlder', [osVersion.value, props.version])
+    );
+    if (!confirmed) {
+      return;
+    }
+  }
+  window.confirmDowngrade?.();
+};
+
 const diagnosticsButton = ref<UserProfileLink | undefined>({
   click: () => {
     window.downloadDiagnostics?.();
@@ -47,9 +86,7 @@ const diagnosticsButton = ref<UserProfileLink | undefined>({
 });
 
 const downgradeButton = ref<UserProfileLink>({
-  click: () => {
-    window.confirmDowngrade?.();
-  },
+  click: startDowngrade,
   name: 'downgrade',
   text: t('updateOs.downgrade.beginDowngradeTo', [props.version]),
 });
@@ -82,6 +119,17 @@ const downgradeButton = ref<UserProfileLink>({
             {{ t('updateOs.downgrade.downloadTheDiagnosticsZipThenPlease') }}
           </p>
         </div>
+        <div
+          v-if="shouldWarnAboutInternalBootDowngrade"
+          class="rounded-md border border-red-200 bg-red-50 px-4 py-3 text-sm leading-relaxed text-red-900"
+        >
+          <p class="font-semibold">
+            {{ t('updateOs.downgrade.internalBootWarningTitle') }}
+          </p>
+          <p>
+            {{ t('updateOs.downgrade.internalBootWarningFrom73xToOlder', [osVersion, version]) }}
+          </p>
+        </div>
       </div>
 
       <div v-if="downgradeButton" class="flex shrink-0 grow flex-col items-stretch gap-4">
diff --git a/web/src/locales/en.json b/web/src/locales/en.json
index f2a96de909..0c0ea869f9 100644
--- a/web/src/locales/en.json
+++ b/web/src/locales/en.json
@@ -804,6 +804,9 @@
   "updateOs.downgrade.downloadDiagnostics": "Download Diagnostics",
   "updateOs.downgrade.downloadTheDiagnosticsZipThenPlease": "Download the Diagnostics zip then please open a bug report on our forums with a description of the issue along with your diagnostics.",
   "updateOs.downgrade.inTheRareEventYouNeed": "In the rare event you need to downgrade we ask that you please provide us with Diagnostics so we can investigate your issue.",
+  "updateOs.downgrade.internalBootConfirmFrom73xToOlder": "WARNING: This server is currently on {0} with internal boot configured. Downgrading to {1} may not support internal boot and could leave the server unbootable until boot media is restored. Do you want to continue anyway?",
+  "updateOs.downgrade.internalBootWarningFrom73xToOlder": "This server is on {0} with internal boot configured. Downgrading to {1} targets a release before internal boot support.",
+  "updateOs.downgrade.internalBootWarningTitle": "Internal boot downgrade risk",
   "updateOs.downgrade.openABugReport": "Open a bug report",
   "updateOs.downgrade.originalReleaseDate": "Original release date {0}",
   "updateOs.downgrade.releaseNotes": "{0} Release Notes",