diff --git a/include/os_dep.h b/include/os_dep.h
index 3a52b829b..cb990de0d 100755
--- a/include/os_dep.h
+++ b/include/os_dep.h
@@ -20,6 +20,7 @@ bool os_is_removable_drive(const char* path);
 bool os_is_network_drive(const char* path);
 bool os_is_local_drive(const char* path);
 bool os_test_disk_free_space(const char* path, unsigned long filesize);
+unsigned long os_get_disk_size(const char* path);
 
 COLOR os_choose_color(COLOR col, WINDOW win);
 void  os_exec_help_command(MENU_TAG tag, const char* key);
diff --git a/include/os_win16.cpp b/include/os_win16.cpp
index 8ba0f8fc7..5151260c0 100755
--- a/include/os_win16.cpp
+++ b/include/os_win16.cpp
@@ -371,6 +371,23 @@ bool os_test_disk_free_space(const char* path, unsigned long filesize)
   return space_ok;
 }
 
+unsigned long os_get_disk_size(const char* path)
+{
+  int disk = 0;
+  if (path && *path && path[1] == ':')
+  {
+    const char letter = toupper(path[0]);
+    disk = 'A' - letter + 1;
+  }  
+  struct _diskfree_t drive;
+  _dos_getdiskfree(disk, &drive);
+                
+  unsigned long bytes = drive.total_clusters;
+  bytes *= drive.sectors_per_cluster;
+  bytes *= drive.bytes_per_sector;
+  return bytes;
+}
+
 void  os_exec_help_command(MENU_TAG tag, const char* key)
 {
   TFilename hlp("prassi.hlp");
diff --git a/include/os_win32.cpp b/include/os_win32.cpp
index 1fb7520b2..d22d36352 100755
--- a/include/os_win32.cpp
+++ b/include/os_win32.cpp
@@ -190,6 +190,18 @@ bool os_test_disk_free_space(const char* path, unsigned long filesize)
   return nFree > filesize;
 }
 
+unsigned long os_get_disk_size(const char* path)
+{
+  DWORD nSecPerClust, nBytePerSec, nFreeClust, nTotalClust;
+  GetDiskFreeSpace(path, &nSecPerClust, &nBytePerSec, &nFreeClust, &nTotalClust);
+  __int64 nFree = nTotalClust;
+  nFree *= nSecPerClust;
+  nFree *= nBytePerSec;
+  unsigned long nVal = nFree > INT_MAX ? (unsigned long)INT_MAX 
+                                       : (unsigned long)nFree;
+  return nVal;
+}
+
 void  os_exec_help_command(MENU_TAG tag, const char* key)
 {
   TFilename hlp("prassi.hlp");