Find a memory leak

A memory leak occurs when a process allocates memory from the paged or nonpaged pools, but doesn't free the memory. As a result, these limited pools of memory are depleted over time, causing Windows to slow down. If memory is completely depleted, failures may result.

In this section

Article Description
Determining Whether a Leak Exists Describes a technique you can use if you aren't sure whether there's a memory leak on your system.
Finding a Kernel-Mode Memory Leak Describes how to find a leak that is caused by a kernel-mode driver or component.
Finding a User-Mode Memory Leak Describes how to find a leak that is caused by a user-mode driver or application.