diff --git a/misc/nsis/install.nsh b/misc/nsis/install.nsh
index fc763474b..fa5b20a72 100755
--- a/misc/nsis/install.nsh
+++ b/misc/nsis/install.nsh
@@ -476,7 +476,7 @@ Function .onInit
       !insertmacro RemoveOld $R0 "/S _?=$0"
     ${endif}
     ${if} $R1 != ""
-      !insertmacro RemoveOld "msiexec.exe" "/X$R1 /passive /promptrestart"
+      !insertmacro RemoveOld "$SYSDIR\msiexec.exe" "/X$R1 /passive /promptrestart"
     ${endif}
   ${endif}
 
diff --git a/misc/nsis/uninstall.nsh b/misc/nsis/uninstall.nsh
index 20add35dd..9d10d05d2 100755
--- a/misc/nsis/uninstall.nsh
+++ b/misc/nsis/uninstall.nsh
@@ -132,7 +132,7 @@ Section "-Uninstall" ; hidden section, must always be the last one!
 
   ; If the uninstaller still exists, use cmd.exe on exit to remove it (along with $INSTDIR if it's empty)
   ${if} ${FileExists} "$INSTDIR\${UNINSTALL_FILENAME}"
-    Exec 'cmd.exe /c (del /f /q "$INSTDIR\${UNINSTALL_FILENAME}") & (rmdir "$INSTDIR")'
+    Exec '"$SYSDIR\cmd.exe" /c (del /f /q "$INSTDIR\${UNINSTALL_FILENAME}") & (rmdir "$INSTDIR")'
   ${endif}
 SectionEnd