If you have Windows Vista/7, click on Start menu and write %temp%.
If you have xp, click on Start menu->Run(Windows Key+R) and execute %temp%. This method also works with Vista/7.
Whatever your temp folder is, because you can change it on the environment variables I assume, will be shown. But IMO legacy software, windows system processes and old viruses use %windir%\temp as %temp% folder.