diff --git a/win/audacity.iss b/win/audacity.iss
index f4da9bfd1..8b7fdb9db 100644
--- a/win/audacity.iss
+++ b/win/audacity.iss
@@ -6,6 +6,11 @@
 ;   Vaughan Johnson, Leland Lucius, Martyn Shaw, Richard Ash, & others
 ;
 
+[UninstallRun]
+; Uninstall prior installations.
+Filename: "{app}\unins*.*"; 
+
+
 [Setup]
 ; compiler-related directives
 OutputBaseFilename=audacity-win-2.0
diff --git a/win/audacity_ansi.iss b/win/audacity_ansi.iss
index d03dab39a..6dc4c1d6f 100644
--- a/win/audacity_ansi.iss
+++ b/win/audacity_ansi.iss
@@ -6,6 +6,11 @@
 ;   Vaughan Johnson, Leland Lucius, Martyn Shaw, Richard Ash, & others
 ;
 
+[UninstallRun]
+; Uninstall prior installations.
+Filename: "{app}\unins*.*"; 
+
+
 [Setup]
 ; compiler-related directives
 OutputBaseFilename=audacity-win-2.0-ansi
diff --git a/win/audacity_unicode.iss b/win/audacity_unicode.iss
index f4da9bfd1..8b7fdb9db 100644
--- a/win/audacity_unicode.iss
+++ b/win/audacity_unicode.iss
@@ -6,6 +6,11 @@
 ;   Vaughan Johnson, Leland Lucius, Martyn Shaw, Richard Ash, & others
 ;
 
+[UninstallRun]
+; Uninstall prior installations.
+Filename: "{app}\unins*.*"; 
+
+
 [Setup]
 ; compiler-related directives
 OutputBaseFilename=audacity-win-2.0