Windows – run 32-bit task manager in windows 7 64-bit

1. Download sysinternals suite from microsoft technet and unpack.
2. Find and run procexp.exe.
3. Click in Options menu on Replace Task Manager and than Restore Task Manager.
4. Click Ctrl+Alt+Del or on taskbar Run Taskmanager. Settings are restored and MS Taskmanager works fine. Because of my habit I can´t work without sysinternals.

There is an overlap in memory used by your applications. When an application is using a DLL, which is a shared library, the library is loaded into the physical memory only once, but every application using it sees an increase in its own memory usage. The Wikipedia article on shared libraries explains memory sharing quite well.

I see that your Windows is not in English, but if you try to translate the fields, I hope this information will help (taken from my Windows 7). The resource monitor can display working set, shareable memory and private memory for each process. Shareable memory and private memory are both combined into the working set of the application. Resident set is part of working set which is in physical memory (RAM) as opposed to being swapped on the hard drive.

So each shared library contributes towards the shareable memory of each application, which is a part of the working set. You have added up all working sets of all applications, I believe.