diff --git a/src/define.sh b/src/define.sh
index cfe9e5098..00e535d46 100644
--- a/src/define.sh
+++ b/src/define.sh
@@ -404,7 +404,7 @@ printVersion() {
 
   if [ -z "$desc" ]; then
     desc="Windows"
-    [[ "${PLATFORM,,}" != "x64" ]] && desc+=" for ${PLATFORM}"
+    isPlatform "x64" || desc+=" for ${PLATFORM}"
   fi
 
   echo "$desc"
diff --git a/src/image.sh b/src/image.sh
index 79a6582d1..5995caf14 100644
--- a/src/image.sh
+++ b/src/image.sh
@@ -1644,7 +1644,7 @@ extractESD() {
   fKill "progress.sh"
   html "$msg..."
 
-  if [[ "${PLATFORM,,}" == "x64" ]]; then
+  if isPlatform "x64"; then
     LABEL="CCCOMA_X64FRE_EN-US_DV9"
   else
     LABEL="CPBA_A64FRE_EN-US_DV9"
diff --git a/src/install.sh b/src/install.sh
index f741ba89e..72f50ccff 100644
--- a/src/install.sh
+++ b/src/install.sh
@@ -387,7 +387,7 @@ startInstall() {
 
   if ! isCustomImage; then
 
-    if [ -s "$BOOT" ]; then
+    if hasImage "$BOOT"; then
       ISO="$TMP/$(basename "$BOOT")"
     else
       ISO="$TMP/$file"
@@ -397,7 +397,7 @@ startInstall() {
 
   # Keep existing media at its persistent path until all storage cleanup has
   # completed successfully, so a later failure cannot strand it under $TMP.
-  if isCustomImage || [ ! -s "$BOOT" ]; then
+  if isCustomImage || ! hasImage "$BOOT"; then
     if ! rm -f -- "$BOOT"; then
       error "Failed to remove obsolete ISO file \"$BOOT\" !"
       return 50
@@ -426,7 +426,7 @@ startInstall() {
 
   # Work from the temporary directory so the persistent source path can
   # later contain either the preserved ISO or the rebuilt installation image.
-  if ! isCustomImage && [ -f "$BOOT" ] && [ -s "$BOOT" ]; then
+  if ! isCustomImage && hasImage "$BOOT"; then
     if ! mv -f -- "$BOOT" "$ISO"; then
       error "Failed to move ISO file from \"$BOOT\" to \"$ISO\" !"
       return 50
@@ -454,7 +454,7 @@ skipUnattended() {
 
   # When automatic preparation fails, inspect extracted media to determine
   # whether it can still be booted manually using legacy firmware.
-  if enabled "$aborted" && [[ "${PLATFORM,,}" == "x64" ]] && [ -d "$dir" ]; then
+  if enabled "$aborted" && isPlatform "x64" && [ -d "$dir" ]; then
 
     efi=$(find "$dir" -maxdepth 1 -type d -iname efi -print -quit) || return 1
     efi32=$(find "$dir" -maxdepth 3 -type f -ipath '*/efi/boot/bootia32.efi' -print -quit) || return 1
@@ -581,7 +581,7 @@ finishInstall() {
 
   local base secure=0
 
-  if [ ! -s "$iso" ] || [ ! -f "$iso" ]; then
+  if ! hasImage "$iso"; then
     error "Failed to find ISO file: $iso" && return 1
   fi
 
@@ -613,7 +613,7 @@ finishInstall() {
     fi
   fi
 
-  if [[ "${PLATFORM,,}" == "x64" ]]; then
+  if isPlatform "x64"; then
     if isLegacyBoot; then
 
       writeState "mode" "$BOOT_MODE" || {
@@ -710,7 +710,7 @@ findFile() {
     file="$STORAGE/$base"
   fi
 
-  if [ ! -f "$file" ] || [ ! -s "$file" ]; then
+  if ! hasImage "$file"; then
     return 0
   fi
 
@@ -777,11 +777,16 @@ isURL() {
   [[ "${value,,}" == "http"* ]]
 }
 
-isLegacyBoot() {
+isPlatform() {
+
+  local platform="$1"
 
-  local mode="${BOOT_MODE:-}"
+  [[ "${PLATFORM,,}" == "${platform,,}" ]]
+}
+
+isLegacyBoot() {
 
-  [[ "${mode,,}" == "windows_legacy" ]]
+  [[ "${BOOT_MODE,,}" == "windows_legacy" ]]
 }
 
 hasBootMarker() {
diff --git a/src/legacy.sh b/src/legacy.sh
index fd936c04c..810151b17 100644
--- a/src/legacy.sh
+++ b/src/legacy.sh
@@ -70,7 +70,7 @@ setMachine() {
 
   esac
 
-  if [[ "${id,,}" == "reactos" ]] && [ -z "$CUSTOM" ]; then
+  if [[ "${id,,}" == "reactos" ]] && ! isCustomImage; then
     # The ISO is a Live-CD so we need to disable the data disk
     # as it will be always wiped during the next runs currently.
     DISK_DISABLE="Y"
@@ -115,7 +115,7 @@ restoreMachine() {
   # Restore the saved machine only when q35 is still the default;
   # an explicit user-selected machine must remain untouched.
   [[ "${MACHINE,,}" != "q35" ]] && return 0
-  [[ "${PLATFORM,,}" != "x64" ]] && return 0
+  isPlatform "x64" || return 0
 
   MACHINE=""
   restoreState "MACHINE" "old" || return 1
@@ -1016,7 +1016,7 @@ detectLegacy() {
   local dir="$1"
   local marker
 
-  [[ "${PLATFORM,,}" == "x64" ]] || return 1
+  isPlatform "x64" || return 1
 
   # Legacy media is identified from setup marker files rather than WIM
   # metadata. The order is intentional because several releases share markers.
diff --git a/src/mido.sh b/src/mido.sh
index db0f5cb4b..fea1d602d 100644
--- a/src/mido.sh
+++ b/src/mido.sh
@@ -320,7 +320,7 @@ downloadWindowsEval() {
       type="iot"
       winVer="windows-11-iot-enterprise-ltsc-eval" ;;
     "win11${PLATFORM,,}-enterprise-ltsc-eval" )
-      if [[ "${PLATFORM,,}" == "arm64" ]]; then
+      if isPlatform "arm64"; then
         type="iot"
         winVer="windows-11-iot-enterprise-ltsc-eval"
       else
@@ -595,7 +595,7 @@ getWindows() {
     "win11${PLATFORM,,}-enterprise"* ) ;;
     * )
 
-      if [[ "${PLATFORM,,}" != "x64" ]]; then
+      if ! isPlatform "x64"; then
         error "No download for the ${PLATFORM^^} platform available for $edition!"
         MIDO_URL=""
         return 1
diff --git a/src/power.sh b/src/power.sh
index 027b830ce..1c93b3c14 100644
--- a/src/power.sh
+++ b/src/power.sh
@@ -346,7 +346,7 @@ sendKey() {
 
 needsBootKey() {
 
-  [ ! -s "$BOOT" ] && return 1
+  hasImage "$BOOT" || return 1
 
   hasCompletedInstall && return 1
   supportsBootKey "$DETECTED" || return 1
@@ -363,7 +363,7 @@ bootKeyReady() {
     return $?
   fi
 
-  if [[ "${PLATFORM,,}" == "arm64" ]]; then
+  if isPlatform "arm64"; then
     grep -Eq "$UEFI_USB_BOOT_PATTERN" "$QEMU_PTY"
   else
     grep -Eq "$UEFI_DVD_BOOT_PATTERN" "$QEMU_PTY"