diff --git a/icu4c/source/common/putil.h b/icu4c/source/common/putil.h
index 603885d3d51..6a623aad11e 100644
--- a/icu4c/source/common/putil.h
+++ b/icu4c/source/common/putil.h
@@ -135,8 +135,11 @@ U_CAPI char*    U_EXPORT2 icu_tzname(int index);
 /* Get UTC (GMT) time measured in seconds since 0:00 on 1/1/70. */
 U_CAPI int32_t  U_EXPORT2 icu_getUTCtime(void);
 
-/* Return the default data directory for this platform.  See Locale. */
-U_CAPI const char*  U_EXPORT2 icu_getDefaultDataDirectory(void);
+/* Return the data directory for this platform. */
+U_CAPI const char* U_EXPORT2 u_getDataDirectory(void);
+
+/* Set the data directory. */
+U_CAPI void U_EXPORT2 u_setDataDirectory(const char *directory);
 
 /* Return the default codepage for this platform and locale */
 U_CAPI const char*  U_EXPORT2 icu_getDefaultCodepage(void);
@@ -155,8 +158,25 @@ U_CAPI const char*  U_EXPORT2 icu_getDefaultLocaleID(void);
  */
 U_CAPI double           U_EXPORT2 icu_nextDouble(double d, bool_t positive);
 
+/*
+ * Filesystem file and path separator characters.
+ * Example: '/' and ':' on Unix, '\\' and ';' on Windows.
+ */
+#ifdef XP_MAC
+#   define U_FILE_SEP_CHAR ':'
+#   define U_PATH_SEP_CHAR ';'
+#   define U_FILE_SEP_STRING ":"
+#   define U_PATH_SEP_STRING ";"
+#elif defined(WIN32) || defined(OS2)
+#   define U_FILE_SEP_CHAR '\\'
+#   define U_PATH_SEP_CHAR ';'
+#   define U_FILE_SEP_STRING "\\"
+#   define U_PATH_SEP_STRING ";"
+#else
+#   define U_FILE_SEP_CHAR '/'
+#   define U_PATH_SEP_CHAR ':'
+#   define U_FILE_SEP_STRING "/"
+#   define U_PATH_SEP_STRING ":"
 #endif
 
-
-
-
+#endif
diff --git a/icu4c/source/common/uloc.c b/icu4c/source/common/uloc.c
index 3530fd88731..8c1c0658e59 100644
--- a/icu4c/source/common/uloc.c
+++ b/icu4c/source/common/uloc.c
@@ -65,7 +65,6 @@ static const UChar closeParen[] = { (UChar)0x0029 /* ( */, (UChar)0x0000};
 
 
 static char* _defaultLocale = NULL;
-static char* _dataDirectory = NULL;
 
 static char** _installedLocales = NULL;
 static int32_t _installedLocalesCount = 0;
@@ -1166,28 +1165,11 @@ const char* const* uloc_getISOCountries()
 const char*
 uloc_getDataDirectory()
 {
-  if (_dataDirectory == NULL) 
-    {
-      uloc_setDataDirectory(icu_getDefaultDataDirectory());
-    }
-  return _dataDirectory;
+  return u_getDataDirectory();
 }
 
 void
 uloc_setDataDirectory(const char* newDirectory) 
 {
-  char* newDataDirectory = (char*) icu_malloc(sizeof(char)*(icu_strlen(newDirectory) + 1));
-  icu_strcpy(newDataDirectory, newDirectory);
-  
-  {
-    umtx_lock(NULL);
-    
-    if(_dataDirectory != NULL)
-      icu_free(_dataDirectory);
-    _dataDirectory = newDataDirectory;
-    if(_installedLocales != NULL)
-      icu_free(_installedLocales);
-    _installedLocales = NULL;
-    umtx_unlock(NULL);
-  }
+  u_setDataDirectory(newDirectory);
 }
diff --git a/icu4c/source/test/cintltst/cucdtst.c b/icu4c/source/test/cintltst/cucdtst.c
index 1af0f6c826a..9baf39c40b9 100644
--- a/icu4c/source/test/cintltst/cucdtst.c
+++ b/icu4c/source/test/cintltst/cucdtst.c
@@ -320,7 +320,7 @@ void TestUnicodeData()
     const char *expectVersion = "3.0.0";  /* NOTE: this purposely breaks to force the tests to stay in sync with the unicodedata */
     char expectString[256];
 
-    strcpy(newPath,icu_getDefaultDataDirectory());
+    strcpy(newPath, u_getDataDirectory());
     strcat(newPath, "UnicodeData-");
     strcat(newPath, expectVersion);
     strcat(newPath, ".txt");
diff --git a/icu4c/source/test/intltest/dtfmrgts.cpp b/icu4c/source/test/intltest/dtfmrgts.cpp
index ae1903b3d19..bba744d07a7 100644
--- a/icu4c/source/test/intltest/dtfmrgts.cpp
+++ b/icu4c/source/test/intltest/dtfmrgts.cpp
@@ -430,7 +430,7 @@ void DateFormatRegressionTest::Test4065240()
 
         // Check to see if the resource is present; if not, we can't test
         ResourceBundle *bundle = new ResourceBundle(
-            icu_getDefaultDataDirectory(), *curLocale, status);
+            u_getDataDirectory(), *curLocale, status);
         failure(status, "new ResourceBundle");
             //(UnicodeString) "java.text.resources.DateFormatZoneData", curLocale);
 
diff --git a/icu4c/source/test/intltest/numrgts.cpp b/icu4c/source/test/intltest/numrgts.cpp
index 37bc4396b70..eebd93db45b 100644
--- a/icu4c/source/test/intltest/numrgts.cpp
+++ b/icu4c/source/test/intltest/numrgts.cpp
@@ -1397,7 +1397,7 @@ void NumberFormatRegressionTest::Test4122840()
     for (int i = 0; i < count; i++) {
         UErrorCode status = U_ZERO_ERROR;
         ResourceBundle *rb = new ResourceBundle(
-            icu_getDefaultDataDirectory()/*"java.text.resources.LocaleElements"*/, 
+            u_getDataDirectory()/*"java.text.resources.LocaleElements"*/, 
             locales[i], status);
         failure(status, "new ResourceBundle");
         //
diff --git a/icu4c/source/test/intltest/ucdtest.cpp b/icu4c/source/test/intltest/ucdtest.cpp
index 55ae14c9eae..cc21086048d 100644
--- a/icu4c/source/test/intltest/ucdtest.cpp
+++ b/icu4c/source/test/intltest/ucdtest.cpp
@@ -304,7 +304,7 @@ void UnicodeTest::TestUnicodeData()
     char path[256];
     const char* datafile = "UnicodeData-3.0.0.txt";
   
-    strcpy(path ,  icu_getDefaultDataDirectory());
+    strcpy(path, u_getDataDirectory());
     strcat(path, datafile);
       
     input = fopen( path, "r");