c++ - GetOpenFileName API intermittently slow on 2003 server -

when running code below on windows server 2003, there intermittent slowdowns while getopenfilename common dialog initializes. startup time varies @ around ~30 seconds. code below scratch program made exemplify problem i'm having in larger project problem exists in both.

one important note, when network interfaces disabled, time taken initialize closer normal - typically ~2 seconds. enabled again, problem returns.

i have put initialization time against other programs file open common dialogs (like notepad) not have same problem, or without network interfaces enabled.

code:

getnewfilename.h:

#define _twinmain wwinmain  #include "windows.h" #include <string> #include "resource.h" using std::wstring;  #define isolation_aware_enabled 1 #if defined _m_ix86 #pragma comment(linker,"/manifestdependency:\"type='win32' name='microsoft.windows.common-controls' version='6.0.0.0' processorarchitecture='x86' publickeytoken='6595b64144ccf1df' language='*'\"") #elif defined _m_ia64 #pragma comment(linker,"/manifestdependency:\"type='win32' name='microsoft.windows.common-controls' version='6.0.0.0' processorarchitecture='ia64' publickeytoken='6595b64144ccf1df' language='*'\"") #elif defined _m_x64 #pragma comment(linker,"/manifestdependency:\"type='win32' name='microsoft.windows.common-controls' version='6.0.0.0' processorarchitecture='amd64' publickeytoken='6595b64144ccf1df' language='*'\"") #else #pragma comment(linker,"/manifestdependency:\"type='win32' name='microsoft.windows.common-controls' version='6.0.0.0' processorarchitecture='*' publickeytoken='6595b64144ccf1df' language='*'\"") #endif  

getnewfilename.cpp:

#include "getnewfilename.h"  hinstance           hinst; bool                initinstance(hinstance); hwnd                hwnd; wstring             lastfile; bool                getnewfilename(hwnd owner, wstring title, wstring defaultfile, lpwstr filetypes, openfilename &ofn, wstring lastdir, wstring lastfile, int mode, wstring extension);  int apientry _twinmain(hinstance hinstance,     hinstance hprevinstance,     lptstr    lpcmdline,     int       ncmdshow) {     unreferenced_parameter(hprevinstance);     unreferenced_parameter(lpcmdline);      msg msg;     haccel hacceltable;      if (!initinstance (hinstance))     {         return false;     }      hacceltable = loadaccelerators(hinstance, makeintresource(idr_accelerator1));      // main message loop:     while (getmessage(&msg, null, 0, 0))     {         if (!translateaccelerator(hwnd, hacceltable, &msg))         {             translatemessage(&msg);             dispatchmessage(&msg);         }     }      return (int) msg.wparam; }  bool initinstance(hinstance hinstance) {     hinst = hinstance;     openfilename ofn;     wstring newfn;     hwnd = createwindow(null, l"test", null,         0, 0, 0, 0, null, null, hinst, null);     bool ret = getnewfilename(hwnd, l"test", l"*.xml", l"xml files\0*.xml\0", ofn, l"c:\\", lastfile, 1, l"xml");     if (ret) {          newfn = ofn.lpstrfile;         messagebox(hwnd,newfn.c_str(),l"test",mb_ok);     }     exitprocess(0);     return true; }  void addprefix(wstring &path) {     wstring test = path.substr(0,4);     if (path.substr(0,8) == l"\\\\?\\unc\\" || path.substr(0,4) == l"\\\\?\\") { return; }     wstring prefix = path.substr(0,2);     if (prefix.compare(l"\\\\") == 0) { path.assign(l"\\\\?\\unc\\"+path.substr(2,wstring::npos)); } else { path.assign(l"\\\\?\\"+path); }     return; }  uint_ptr callback ofnhookproc(hwnd hdlg, uint uimsg, wparam wparam, lparam lparam) {     hicon hicon;     int width, height, xleft, ytop;     rect recttocenteron, rectsubdialog;     switch (uimsg) {     case wm_initdialog:         hicon = loadicon(hinst, makeintresource(idi_pmmico));         sendmessage(getparent(hdlg), wm_seticon, icon_big, (lparam)hicon);          sendmessage(getparent(hdlg), wm_seticon, icon_small, (lparam)hicon);          getwindowrect(getdesktopwindow(), &recttocenteron);         getwindowrect(getparent(hdlg), &rectsubdialog);         width = rectsubdialog.right-rectsubdialog.left;         height = rectsubdialog.bottom-rectsubdialog.top;         xleft = recttocenteron.right / 2 -              (width) / 2;         ytop = recttocenteron.bottom / 2 -              (height) / 2;         bool test  = setwindowpos(getparent(hdlg), null, xleft, ytop, width, height, swp_nosize);         return (int_ptr)false;         break;     }     return (int_ptr)false; }  bool getnewfilename(hwnd owner, wstring title, wstring defaultfile, lpwstr filetypes, openfilename &ofn, wstring lastdir, wstring lastfile, int mode, wstring extension) {     wstring lastdir_pre(lastdir);     addprefix(lastdir_pre);     if (lastfile.compare(l"") == 0) { lastfile = defaultfile; }     bool ret = false;     wchar_t buffer[30000];     ofn.lstructsize = sizeof(openfilename);     ofn.hwndowner = owner;     ofn.lpstrfile = buffer;     lastfile.copy(ofn.lpstrfile,lastfile.size(),0);     ofn.lpstrfile[lastfile.size()] = '\0';     ofn.nmaxfile = 30000;     ofn.flags = ofn_overwriteprompt | ofn_enablehook | ofn_explorer;     ofn.lpfnhook = ofnhookproc;     ofn.lpstrfilter = filetypes;     ofn.lpstrcustomfilter = null;     ofn.nfilterindex = 0;     ofn.lpstrinitialdir = lastdir_pre.c_str();     ofn.lpstrfiletitle = null;     ofn.lpstrdefext = extension.c_str();     ofn.lpstrtitle = title.c_str();     if (mode == 1) {         ofn.flags = ofn.flags | ofn_pathmustexist;         ret = getopenfilename(&ofn);      } else if (mode == 2) {         ret = getsavefilename(&ofn);      }     if (ret == false) { ofn.lpstrfile[0] = '\0'; }     return ret; }