Use Performance Monitor to find a user-mode memory leak
If you suspect there's a user-mode memory leak but aren't sure which process causes it, use Performance Monitor to measure the memory usage of individual processes.
Run Performance Monitor as Administrator. Add the following counters:
Process > Private Bytes (for each process you want to examine)
Process > Virtual Bytes (for each process you wish to examine)
Change the update time to 600 seconds to capture a graph of the leak over time. You might also want to log the data to a file for later examination.
The Private Bytes counter indicates the total amount of memory that a process has allocated, not including memory shared with other processes.
The Virtual Bytes counter indicates the current size of the virtual address space that the process uses.
Some memory leaks appear in the data file in the form of an increase in private bytes allocated. Other memory leaks show up in the form of an increase in the virtual address space.
After you've determined which process is leaking memory, use the UMDH tool to determine the specific routine that's at fault. For details, see Using UMDH to find user-mode memory leaks.