diff --git a/pkg/win32/installer.iss.in b/pkg/win32/installer.iss.in
index 299d7e27..245f5d93 100644
--- a/pkg/win32/installer.iss.in
+++ b/pkg/win32/installer.iss.in
@@ -103,7 +103,8 @@ begin
   begin
 	UpgradeMode := True;
     RegQueryStringValue(HKEY_LOCAL_MACHINE,'Software\{#MyAppName}\{#MyAppVersion}', 'Version', Version);
-    if Version > '{#MyAppFullVersion}' then
+    //pgAdmin version can be converted to float directly
+    if StrToFloat(Version) > StrToFloat('{#MyAppFullVersion}') then
     begin
       MsgBox(ExpandConstant('{cm:NewerVersionExists}' + '(v' + Version + ') is already installed' ), mbInformation, MB_OK);
       Result := False;