diff --git a/xpinstall/src/nsLoggingProgressNotifier.cpp b/xpinstall/src/nsLoggingProgressNotifier.cpp
index e20c38de882d..a54b0fdcd0a1 100644
--- a/xpinstall/src/nsLoggingProgressNotifier.cpp
+++ b/xpinstall/src/nsLoggingProgressNotifier.cpp
@@ -270,14 +270,19 @@ nsLoggingProgressListener::OnItemScheduled(const PRUnichar* message )
 }
 
 NS_IMETHODIMP
-nsLoggingProgressListener::OnFinalizeProgress(const PRUnichar* message, PRInt32 itemNum, PRInt32 totNum )
+nsLoggingProgressListener::OnFinalizeProgress(const PRUnichar* aMessage, PRInt32 aItemNum, PRInt32 aTotNum )
 {
     nsCString messageConverted;
-    messageConverted.AssignWithConversion(message);
+
+    // this Lossy conversion is safe because the input source came from a
+    // similar fake-ascii-to-not-really-unicode conversion.
+    // If you use NS_CopyUnicodeToNative(), it'll crash under a true JA WinXP
+    // system as opposed to a EN winXP system changed to JA.
+    messageConverted.AssignWithConversion(aMessage);
 
     if (mLogStream == nsnull) return NS_ERROR_NULL_POINTER;
 
-    *mLogStream << "     [" << (itemNum) << "/" << totNum << "]\t" << messageConverted.get() << nsEndl;
+    *mLogStream << "     [" << (aItemNum) << "/" << aTotNum << "]\t" << messageConverted.get() << nsEndl;
     return NS_OK;
 }
 
@@ -292,11 +297,11 @@ nsLoggingProgressListener::GetTime(char** aString)
 }
 
 NS_IMETHODIMP
-nsLoggingProgressListener::OnLogComment(const PRUnichar* comment)
+nsLoggingProgressListener::OnLogComment(const PRUnichar* aComment)
 {
     nsCString commentConverted;
-    commentConverted.AssignWithConversion(comment);
 
+    NS_CopyUnicodeToNative(nsDependentString(aComment), commentConverted);
     if (mLogStream == nsnull) return NS_ERROR_NULL_POINTER;
 
     *mLogStream << "     ** " << commentConverted.get() << nsEndl;
diff --git a/xpinstall/wizard/windows/setup/extra.c b/xpinstall/wizard/windows/setup/extra.c
index c2af0b4a2b68..8f49bd4b8551 100644
--- a/xpinstall/wizard/windows/setup/extra.c
+++ b/xpinstall/wizard/windows/setup/extra.c
@@ -3482,7 +3482,7 @@ void RestoreInvisibleFlag(siC *siCNode)
 
   GetPrivateProfileString(siCNode->szReferenceName, "Attributes", "", szBuf, sizeof(szBuf), szFileIniConfig);
   lstrcpy(szAttribute, szBuf);
-  strupr(szAttribute);
+  CharUpperBuff(szAttribute, sizeof(szAttribute));
 
   if(strstr(szAttribute, "INVISIBLE") || siCNode->bSupersede)
     siCNode->dwAttributes |= SIC_INVISIBLE;
@@ -3497,7 +3497,7 @@ void RestoreAdditionalFlag(siC *siCNode)
 
   GetPrivateProfileString(siCNode->szReferenceName, "Attributes", "", szBuf, sizeof(szBuf), szFileIniConfig);
   lstrcpy(szAttribute, szBuf);
-  strupr(szAttribute);
+  CharUpperBuff(szAttribute, sizeof(szAttribute));
 
   if(strstr(szAttribute, "ADDITIONAL") && !strstr(szAttribute, "NOTADDITIONAL"))
     siCNode->dwAttributes |= SIC_ADDITIONAL;
@@ -4470,7 +4470,7 @@ DWORD ParseOSType(char *szOSType)
   DWORD dwOSType = 0;
 
   lstrcpy(szBuf, szOSType);
-  strupr(szBuf);
+  CharUpperBuff(szBuf, sizeof(szBuf));
 
   if(strstr(szBuf, "WIN95 DEBUTE"))
     dwOSType |= OS_WIN95_DEBUTE;
@@ -4500,7 +4500,7 @@ HRESULT ParseComponentAttributes(char *szAttribute, DWORD dwAttributes, BOOL bOv
   char  szBuf[MAX_BUF];
 
   lstrcpy(szBuf, szAttribute);
-  strupr(szBuf);
+  CharUpperBuff(szBuf, sizeof(szBuf));
 
   if(bOverride != TRUE)
   {
@@ -8391,8 +8391,8 @@ int AddGrePathToApplicationAppPathsKey()
     rv = APPPATH_GRE_PATH_SET;
     MozCopyStr(path, keyPathUpr, sizeof(keyPathUpr));
     MozCopyStr(gGre.homePath, grePathUpr, sizeof(grePathUpr));
-    strupr(grePathUpr);
-    strupr(keyPathUpr);
+    CharUpperBuff(grePathUpr, sizeof(grePathUpr));
+    CharUpperBuff(keyPathUpr, sizeof(keyPathUpr));
     if(!strstr(keyPathUpr, grePathUpr))
       wsprintf(newPath, "%s;%s", gGre.homePath, path);
     else
diff --git a/xpinstall/wizard/windows/uninstall/parser.c b/xpinstall/wizard/windows/uninstall/parser.c
index fc39f4e9b413..12088d5b92d7 100644
--- a/xpinstall/wizard/windows/uninstall/parser.c
+++ b/xpinstall/wizard/windows/uninstall/parser.c
@@ -498,13 +498,13 @@ BOOL DetermineUnRegisterServer(sil *silInstallLogHead, LPSTR szFile)
     silInstallLogTemp = silInstallLogHead;
     iSharedFileCount  = GetSharedFileCount(szFile);
     lstrcpy(szLCFile, szFile);
-    _strlwr(szLCFile);
+    CharLowerBuff(szLCFile, sizeof(szLCLine));
 
     do
     {
       silInstallLogTemp = silInstallLogTemp->Prev;
       lstrcpy(szLCLine, silInstallLogTemp->szLine);
-      _strlwr(szLCLine);
+      CharLowerBuff(szLCLine, sizeof(szLCLine));
 
       if((strstr(szLCLine, szLCFile) != NULL) &&
          (strstr(szLCLine, KEY_INSTALLING_SHARED_FILE) != NULL) &&
@@ -570,7 +570,7 @@ DWORD Uninstall(sil* silInstallLogHead)
     {
       silInstallLogTemp = silInstallLogTemp->Prev;
       lstrcpy(szLCLine, silInstallLogTemp->szLine);
-      _strlwr(szLCLine);
+      CharLowerBuff(szLCLine, sizeof(szLCLine));
 
       if(((szSubStr = strstr(szLCLine, KEY_WINDOWS_REGISTER_SERVER)) != NULL) &&
           (strstr(szLCLine, KEY_DO_NOT_UNINSTALL) == NULL))
diff --git a/xpinstall/wizard/windows/uninstall/rdi.c b/xpinstall/wizard/windows/uninstall/rdi.c
index 4225d8339cb5..0fc353157428 100644
--- a/xpinstall/wizard/windows/uninstall/rdi.c
+++ b/xpinstall/wizard/windows/uninstall/rdi.c
@@ -223,7 +223,7 @@ BOOL DdeexecCheck(char *szKey, char *szValue)
   BOOL bPass = TRUE;
 
   lstrcpy(szKeyLower, szKey);
-  strlwr(szKeyLower);
+  CharLowerBuff(szKeyLower, sizeof(szKeyLower));
   if(strstr(szKeyLower, szKddeexec) && CheckForNonPrintableChars(szValue))
     bPass = FALSE;
 
@@ -392,7 +392,7 @@ int GetUninstallAppPathName(char *szAppPathName, DWORD dwAppPathNameSize)
   }
 
   GetWinReg(hkRoot, szKey, "PathToExe", szAppPathName, dwAppPathNameSize);
-  strupr(szAppPathName);
+  CharUpperBuff(szAppPathName, dwAppPathNameSize);
   return(CMI_OK);
 }
 
@@ -513,7 +513,7 @@ BOOL GetUnreadMailKeyList(char *szUninstallAppPathName, skn **sknWinRegKeyList)
                                szBuf,
                                &dwBufSize) == ERROR_SUCCESS)
             {
-              strupr(szBuf);
+              CharUpperBuff(szBuf, sizeof(szBuf));
               if(strstr(szBuf, szUninstallAppPathName) != NULL)
               {
                 bFoundAtLeastOne = TRUE;