--- a/QTfrontend/hwform.cpp	Mon Mar 04 13:44:33 2013 +0100
+++ b/QTfrontend/hwform.cpp	Mon Mar 04 15:16:06 2013 +0100
@@ -1860,8 +1860,8 @@
 QString HWForm::getDemoArguments()
 {
 
-    QString prefix = datadir->absolutePath();
-    QString userPrefix = cfgdir->absolutePath();
+    QString prefix = "\"" + datadir->absolutePath() + "\"";
+    QString userPrefix = "\"" + cfgdir->absolutePath() + "\"";
 #ifdef Q_WS_WIN
     prefix = prefix.replace("/","\\");
     userPrefix = userPrefix.replace("/","\\");
@@ -1897,8 +1897,8 @@
     registry_hkcr.setValue("Hedgewars.Save/Default", tr("Hedgewars Save File", "File Types"));
     registry_hkcr.setValue("Hedgewars.Demo/DefaultIcon/Default", "\"" + bindir->absolutePath().replace("/", "\\") + "\\hwdfile.ico\",0");
     registry_hkcr.setValue("Hedgewars.Save/DefaultIcon/Default", "\"" + bindir->absolutePath().replace("/", "\\") + "\\hwsfile.ico\",0");
-    registry_hkcr.setValue("Hedgewars.Demo/Shell/Open/Command/Default", "\"" + bindir->absolutePath().replace("/", "\\") + "\\hwengine.exe\" \"%1\" "+arguments);
-    registry_hkcr.setValue("Hedgewars.Save/Shell/Open/Command/Default", "\"" + bindir->absolutePath().replace("/", "\\") + "\\hwengine.exe\" \"%1\" "+arguments);
+    registry_hkcr.setValue("Hedgewars.Demo/Shell/Open/Command/Default", "\"" + bindir->absolutePath().replace("/", "\\") + "\\hwengine.exe\" " + arguments + " %1");
+    registry_hkcr.setValue("Hedgewars.Save/Shell/Open/Command/Default", "\"" + bindir->absolutePath().replace("/", "\\") + "\\hwengine.exe\" " + arguments + " %1");
 #elif defined __APPLE__
     // only useful when other apps have taken precedence over our file extensions and you want to reset it
     system("defaults write com.apple.LaunchServices LSHandlers -array-add '<dict><key>LSHandlerContentTag</key><string>hwd</string><key>LSHandlerContentTagClass</key><string>public.filename-extension</string><key>LSHandlerRoleAll</key><string>org.hedgewars.desktop</string></dict>'");