diff --git a/profile/pref-migrator/src/nsPrefMigration.cpp b/profile/pref-migrator/src/nsPrefMigration.cpp
index c1b275078572..258562231774 100644
--- a/profile/pref-migrator/src/nsPrefMigration.cpp
+++ b/profile/pref-migrator/src/nsPrefMigration.cpp
@@ -55,7 +55,7 @@
 #include "prio.h"
 #include "prerror.h"
 #include "prmem.h"
-#include "nsIPref.h"
+#include "nsIPrefService.h"
 #include "plstr.h"
 #include "prprf.h"
 #include "nsXPIDLString.h"
@@ -284,12 +284,12 @@ nsPrefMigration::getPrefService()
   // get the prefs service
   nsresult rv = NS_OK;
 
-  nsCOMPtr<nsIPref> pIMyService(do_GetService(NS_PREF_CONTRACTID, &rv));
+  nsCOMPtr<nsIPrefBranch> pIMyService(do_GetService(NS_PREFSERVICE_CONTRACTID, &rv));
   if(NS_FAILED(rv)) return rv;
 
-  return NS_GetProxyForObject(NS_PROXY_TO_MAIN_THREAD, NS_GET_IID(nsIPref),
+  return NS_GetProxyForObject(NS_PROXY_TO_MAIN_THREAD, NS_GET_IID(nsIPrefBranch),
                               pIMyService, NS_PROXY_SYNC,
-                              getter_AddRefs(m_prefs));
+                              getter_AddRefs(m_prefBranch));
 
 }
 
@@ -635,11 +635,13 @@ nsPrefMigration::ProcessPrefsCallback(const char* oldProfilePathStr, const char
   rv = m_prefsFile->AppendNative(NS_LITERAL_CSTRING(PREF_FILE_NAME_IN_4x));
   if (NS_FAILED(rv)) return rv;
 
+  nsCOMPtr<nsIPrefService> psvc(do_QueryInterface(m_prefBranch));
+
   //Clear the prefs in case a previous set was read in.
-  m_prefs->ResetPrefs();
+  psvc->ResetPrefs();
 
   //Now read the prefs from the prefs file in the system directory
-  m_prefs->ReadUserPrefs(m_prefsFile);
+  psvc->ReadUserPrefs(m_prefsFile);
 
   //
   // Start computing the sizes required for migration
@@ -647,11 +649,12 @@ nsPrefMigration::ProcessPrefsCallback(const char* oldProfilePathStr, const char
   rv = GetSizes(oldProfileSpec, PR_FALSE, &totalProfileSize);
   profileDrive = newProfileSpec.GetDiskSpaceAvailable();
 
-  rv = m_prefs->GetIntPref(PREF_MAIL_SERVER_TYPE, &serverType);
+  rv = m_prefBranch->GetIntPref(PREF_MAIL_SERVER_TYPE, &serverType);
   if (NS_FAILED(rv)) return rv;
 
   // get the migration mode for mail
-  rv = m_prefs->GetBoolPref(PREF_MIGRATION_MODE_FOR_MAIL, &copyMailFileInMigration);
+  rv = m_prefBranch->GetBoolPref(PREF_MIGRATION_MODE_FOR_MAIL,
+                                 &copyMailFileInMigration);
   if (NS_FAILED(rv))
     return rv;
 
@@ -871,11 +874,13 @@ nsPrefMigration::ProcessPrefsCallback(const char* oldProfilePathStr, const char
       NS_FileSpecToIFile(&newPOPMailPathSpec,
                          getter_AddRefs(newPOPMailPathFile));
       
-      rv = m_prefs->SetFileXPref(PREF_MAIL_DIRECTORY, newPOPMailPathFile); 
+      rv = m_prefBranch->SetComplexValue(PREF_MAIL_DIRECTORY,
+                                         NS_GET_IID(nsILocalFile),
+                                         newPOPMailPathFile);
       if (NS_FAILED(rv)) return rv;
     }
 
-    m_prefs->CopyCharPref(PREF_NETWORK_HOSTS_POP_SERVER, &popServerName);
+    m_prefBranch->GetCharPref(PREF_NETWORK_HOSTS_POP_SERVER, &popServerName);
 
     nsCAutoString popServerNamewithoutPort(popServerName);
     PRInt32 colonPos = popServerNamewithoutPort.FindChar(':');
@@ -926,7 +931,9 @@ nsPrefMigration::ProcessPrefsCallback(const char* oldProfilePathStr, const char
       NS_FileSpecToIFile(&newIMAPLocalMailPathSpec,
                          getter_AddRefs(newIMAPLocalMailPathFile));
       
-      rv = m_prefs->SetFileXPref(PREF_MAIL_DIRECTORY, newIMAPLocalMailPathFile); 
+      rv = m_prefBranch->SetComplexValue(PREF_MAIL_DIRECTORY,
+                                         NS_GET_IID(nsILocalFile),
+                                         newIMAPLocalMailPathFile);
       if (NS_FAILED(rv)) return rv;
     }
 
@@ -966,7 +973,9 @@ nsPrefMigration::ProcessPrefsCallback(const char* oldProfilePathStr, const char
       NS_FileSpecToIFile(&newIMAPMailPathSpec,
                          getter_AddRefs(newIMAPMailPathFile));
       
-      rv = m_prefs->SetFileXPref(PREF_MAIL_IMAP_ROOT_DIR, newIMAPMailPathFile);
+      rv = m_prefBranch->SetComplexValue(PREF_MAIL_IMAP_ROOT_DIR,
+                                         NS_GET_IID(nsILocalFile),
+                                         newIMAPMailPathFile);
       if (NS_FAILED(rv)) return rv;
     }
    }
@@ -981,7 +990,9 @@ nsPrefMigration::ProcessPrefsCallback(const char* oldProfilePathStr, const char
       NS_FileSpecToIFile(&oldIMAPLocalMailPathSpec,
                          getter_AddRefs(oldIMAPLocalMailPathFile));
 
-      rv = m_prefs->SetFileXPref(PREF_MAIL_DIRECTORY, oldIMAPLocalMailPathFile);
+      rv = m_prefBranch->SetComplexValue(PREF_MAIL_DIRECTORY,
+                                         NS_GET_IID(nsILocalFile),
+                                         oldIMAPLocalMailPathFile);
       if (NS_FAILED(rv)) return rv;
     }
     {
@@ -993,7 +1004,9 @@ nsPrefMigration::ProcessPrefsCallback(const char* oldProfilePathStr, const char
       NS_FileSpecToIFile(&oldIMAPMailPathSpec,
                          getter_AddRefs(oldIMAPMailPathFile));
 
-      rv = m_prefs->SetFileXPref(PREF_MAIL_IMAP_ROOT_DIR, oldIMAPMailPathFile);
+      rv = m_prefBranch->SetComplexValue(PREF_MAIL_IMAP_ROOT_DIR,
+                                         NS_GET_IID(nsILocalFile),
+                                         oldIMAPMailPathFile);
       if (NS_FAILED(rv)) return rv;
     }
    }
@@ -1028,7 +1041,9 @@ nsPrefMigration::ProcessPrefsCallback(const char* oldProfilePathStr, const char
       NS_FileSpecToIFile(&newMOVEMAILPathSpec,
                          getter_AddRefs(newMOVEMAILPathFile));
       
-      rv = m_prefs->SetFileXPref(PREF_MAIL_DIRECTORY, newMOVEMAILPathFile); 
+      rv = m_prefBranch->SetComplexValue(PREF_MAIL_DIRECTORY,
+                                         NS_GET_IID(nsILocalFile),
+                                         newMOVEMAILPathFile); 
       if (NS_FAILED(rv)) return rv;
     }
 
@@ -1079,7 +1094,9 @@ nsPrefMigration::ProcessPrefsCallback(const char* oldProfilePathStr, const char
     NS_FileSpecToIFile(&newNewsPathSpec,
                        getter_AddRefs(newNewsPathFile));
     
-    rv = m_prefs->SetFileXPref(PREF_NEWS_DIRECTORY, newNewsPathFile); 
+    rv = m_prefBranch->SetComplexValue(PREF_NEWS_DIRECTORY,
+                                       NS_GET_IID(nsILocalFile),
+                                       newNewsPathFile); 
     if (NS_FAILED(rv)) return rv;
   }
 
@@ -1192,7 +1209,7 @@ nsPrefMigration::ProcessPrefsCallback(const char* oldProfilePathStr, const char
   
   // Don't inherit the 4.x cache file location for mozilla!
   // The cache pref later gets set with a default in nsAppRunner::InitCachePrefs().
-  m_prefs->ClearUserPref(PREF_BROWSER_CACHE_DIRECTORY);
+  m_prefBranch->ClearUserPref(PREF_BROWSER_CACHE_DIRECTORY);
 
   rv = DoSpecialUpdates(newProfilePath);
   if (NS_FAILED(rv)) return rv;
@@ -1206,9 +1223,9 @@ nsPrefMigration::ProcessPrefsCallback(const char* oldProfilePathStr, const char
   rv = newPrefsFile->AppendNative(NS_LITERAL_CSTRING(PREF_FILE_NAME_IN_5x));
   if (NS_FAILED(rv)) return rv;
 
-  rv=m_prefs->SavePrefFile(newPrefsFile);
+  rv=psvc->SavePrefFile(newPrefsFile);
   if (NS_FAILED(rv)) return rv;
-  rv=m_prefs->ResetPrefs();
+  rv=psvc->ResetPrefs();
   if (NS_FAILED(rv)) return rv;
 
   PRBool flagExists = PR_FALSE;
@@ -1316,7 +1333,7 @@ nsPrefMigration::GetDirFromPref(nsIFileSpec * oldProfilePath, nsIFileSpec * newP
   
   nsCOMPtr <nsIFileSpec> oldPrefPath;
   nsXPIDLCString oldPrefPathStr;
-  rv = m_prefs->CopyCharPref(pref,getter_Copies(oldPrefPathStr));
+  rv = m_prefBranch->GetCharPref(pref, getter_Copies(oldPrefPathStr));
   if (NS_FAILED(rv)) return rv;
   
   // the default on the mac was "".  doing GetFileXPref on that would return
@@ -1327,7 +1344,8 @@ nsPrefMigration::GetDirFromPref(nsIFileSpec * oldProfilePath, nsIFileSpec * newP
   if (NS_FAILED(rv)) return rv;
   
   nsCOMPtr <nsILocalFile> oldPrefPathFile;
-  rv = m_prefs->GetFileXPref(pref, getter_AddRefs(oldPrefPathFile));
+  rv = m_prefBranch->GetComplexValue(pref, NS_GET_IID(nsILocalFile),
+                                     getter_AddRefs(oldPrefPathFile));
   if (NS_FAILED(rv)) return rv;
   
   // convert nsILocalFile to nsIFileSpec
@@ -1966,7 +1984,7 @@ nsPrefMigration::DoSpecialUpdates(nsIFileSpec  * profilePath)
   if (NS_FAILED(rv)) return rv;
     
   /* Create the new mail directory from the setting in prefs.js or a default */
-  rv = m_prefs->GetIntPref(PREF_MAIL_SERVER_TYPE, &serverType);
+  rv = m_prefBranch->GetIntPref(PREF_MAIL_SERVER_TYPE, &serverType);
   if (NS_FAILED(rv)) return rv; 
   if (serverType == POP_4X_MAIL_TYPE) {
 	rv = RenameAndMove4xPopFilterFile(profilePath);
@@ -2020,7 +2038,7 @@ nsPrefMigration::RenameAndMove4xPopFile(nsIFileSpec * profilePath, const char *f
   nsFileSpec migratedPopDirectory;
   rv = profilePath->GetFileSpec(&migratedPopDirectory);
   migratedPopDirectory += NEW_MAIL_DIR_NAME;
-  m_prefs->CopyCharPref(PREF_NETWORK_HOSTS_POP_SERVER, &popServerName);
+  m_prefBranch->GetCharPref(PREF_NETWORK_HOSTS_POP_SERVER, &popServerName);
   migratedPopDirectory += popServerName;
   PR_FREEIF(popServerName);
 
@@ -2089,7 +2107,7 @@ nsPrefMigration::RenameAndMove4xImapFilterFiles(nsIFileSpec * profilePath)
   nsresult rv;
   char *hostList=nsnull;
 
-  rv = m_prefs->CopyCharPref(PREF_4X_NETWORK_HOSTS_IMAP_SERVER, &hostList);
+  rv = m_prefBranch->GetCharPref(PREF_4X_NETWORK_HOSTS_IMAP_SERVER, &hostList);
   if (NS_FAILED(rv)) return rv;
 
   if (!hostList || !*hostList) return NS_OK; 
@@ -2154,7 +2172,9 @@ nsPrefMigration::GetPremigratedFilePref(const char *pref_name, nsIFileSpec **pat
 #ifdef DEBUG_seth
         printf("getting %s (into a nsFileSpec)\n", premigration_pref);
 #endif
-        rv = m_prefs->GetFilePref((const char *)premigration_pref, path);
+        rv = m_prefBranch->GetComplexValue((const char *)premigration_pref,
+                                           NS_GET_IID(nsIFileSpec),
+                                           (void **)path);
         return rv;
 }
 
@@ -2192,8 +2212,9 @@ nsPrefMigration::SetPremigratedFilePref(const char *pref_name, nsIFileSpec *path
   NS_ASSERTION(exists, "the path does not exist.  see bug #55444");
   if (!exists) return NS_OK;
   
-	rv = m_prefs->SetFileXPref((const char *)premigration_pref, pathFile);
-	return rv;
+  rv = m_prefBranch->SetComplexValue((const char *)premigration_pref,
+                                     NS_GET_IID(nsILocalFile), pathFile);
+  return rv;
 }
 
 nsresult 
@@ -2334,7 +2355,7 @@ ConvertStringToUTF8(const char* aCharset, const char* inString, char** outString
 }
 
 nsresult
-ConvertPrefToUTF8(const char *prefname, nsIPref *prefs, const char* charSet)
+ConvertPrefToUTF8(const char *prefname, nsIPrefBranch *prefs, const char* charSet)
 {
     nsresult rv;
 
@@ -2345,7 +2366,7 @@ ConvertPrefToUTF8(const char *prefname, nsIPref *prefs, const char* charSet)
     
     nsXPIDLCString prefval;
 
-    rv = prefs->CopyCharPref(prefname, getter_Copies(prefval));
+    rv = prefs->GetCharPref(prefname, getter_Copies(prefval));
     if (NS_FAILED(rv)) return rv;
 
     if (prefval.IsEmpty()) {
@@ -2384,10 +2405,8 @@ static PRBool charEndsWith(const char *str, const char *endStr)
 }
 
 static
-void fontPrefEnumerationFunction(const char *name, void *data)
+void fontPrefEnumerationFunction(const char *name, nsCStringArray *arr)
 {
-  nsCStringArray *arr;
-  arr = (nsCStringArray *)data;
 #ifdef DEBUG_UTF8_CONVERSION
   printf("fontPrefEnumerationFunction: %s\n", name);
 #endif 
@@ -2399,10 +2418,8 @@ void fontPrefEnumerationFunction(const char *name, void *data)
 }
 
 static
-void ldapPrefEnumerationFunction(const char *name, void *data)
+void ldapPrefEnumerationFunction(const char *name, nsCStringArray *arr)
 {
-  nsCStringArray *arr;
-  arr = (nsCStringArray *)data;
 #ifdef DEBUG_UTF8_CONVERSION
   printf("ldapPrefEnumerationFunction: %s\n", name);
 #endif 
@@ -2415,10 +2432,8 @@ void ldapPrefEnumerationFunction(const char *name, void *data)
 }
 
 static
-void vCardPrefEnumerationFunction(const char *name, void *data)
+void vCardPrefEnumerationFunction(const char *name, nsCStringArray *arr)
 {
-  nsCStringArray *arr;
-  arr = (nsCStringArray *)data;
 #ifdef DEBUG_UTF8_CONVERSION
   printf("vCardPrefEnumerationFunction: %s\n", name);
 #endif 
@@ -2430,7 +2445,7 @@ void vCardPrefEnumerationFunction(const char *name, void *data)
 
 
 typedef struct {
-    nsIPref *prefs;
+    nsIPrefBranch *prefs;
     const char* charSet;
 } PrefEnumerationClosure;
 
@@ -2451,7 +2466,7 @@ nsPrefConverter::ConvertPrefsToUTF8()
 
   nsCStringArray prefsToMigrate;
 
-  nsCOMPtr<nsIPref> prefs(do_GetService(NS_PREF_CONTRACTID, &rv));
+  nsCOMPtr<nsIPrefBranch> prefs(do_GetService(NS_PREFSERVICE_CONTRACTID, &rv));
   if(NS_FAILED(rv)) return rv;
   if (!prefs) return NS_ERROR_FAILURE;
 
@@ -2465,9 +2480,29 @@ nsPrefConverter::ConvertPrefsToUTF8()
     prefsToMigrate.AppendCString(prefnameStr);
   }
 
-  prefs->EnumerateChildren("intl.font",fontPrefEnumerationFunction,(void *)(&prefsToMigrate));
-  prefs->EnumerateChildren("ldap_2.servers",ldapPrefEnumerationFunction,(void *)(&prefsToMigrate));
-  prefs->EnumerateChildren("mail.identity.vcard",vCardPrefEnumerationFunction,(void *)(&prefsToMigrate));
+  PRUint32 count, i;
+  char **childArray;
+
+  if (NS_SUCCEEDED(prefs->GetChildList("intl.font.", &count, &childArray))) {
+    for (i = 0; i < count; i++)
+      fontPrefEnumerationFunction(childArray[i], &prefsToMigrate);
+
+    NS_FREE_XPCOM_ALLOCATED_POINTER_ARRAY(count, childArray);
+  }
+
+  if (NS_SUCCEEDED(prefs->GetChildList("ldap_2.servers.", &count, &childArray))) {
+    for (i = 0; i < count; i++)
+      ldapPrefEnumerationFunction(childArray[i], &prefsToMigrate);
+
+    NS_FREE_XPCOM_ALLOCATED_POINTER_ARRAY(count, childArray);
+  }
+
+  if (NS_SUCCEEDED(prefs->GetChildList("mail.identity.vcard.", &count, &childArray))) {
+    for (i = 0; i < count; i++)
+      vCardPrefEnumerationFunction(childArray[i], &prefsToMigrate);
+
+    NS_FREE_XPCOM_ALLOCATED_POINTER_ARRAY(count, childArray);
+  }
 
   PrefEnumerationClosure closure;
 
@@ -2476,7 +2511,7 @@ nsPrefConverter::ConvertPrefsToUTF8()
 
   prefsToMigrate.EnumerateForwards((nsCStringArrayEnumFunc)convertPref, (void *)(&closure));
 
-  rv = prefs->SetBoolPref("prefs.converted-to-utf8",PR_TRUE);
+  rv = prefs->SetBoolPref("prefs.converted-to-utf8", PR_TRUE);
   return NS_OK;
 }
 
diff --git a/profile/pref-migrator/src/nsPrefMigration.h b/profile/pref-migrator/src/nsPrefMigration.h
index e40190a06c07..fe6dbae5ef83 100644
--- a/profile/pref-migrator/src/nsPrefMigration.h
+++ b/profile/pref-migrator/src/nsPrefMigration.h
@@ -43,7 +43,7 @@
 #include "nsIFactory.h"
 #include "nsISupports.h"
 #include "nsFileSpec.h"
-#include "nsIPref.h"
+#include "nsIPrefBranch.h"
 #include "nsIServiceManager.h"
 #include "nsCOMPtr.h"
 #include "nsIDOMWindowInternal.h"
@@ -176,7 +176,7 @@ class nsPrefMigration: public nsIPrefMigration
 
       nsresult getPrefService();
 
-      nsCOMPtr<nsIPref>         m_prefs;
+      nsCOMPtr<nsIPrefBranch>    m_prefBranch;
       nsCOMPtr<nsILocalFile>     m_prefsFile; 
       nsCOMPtr<nsIDOMWindowInternal>    m_parentWindow;
       nsCOMPtr<nsIDOMWindow>    mPMProgressWindow;