Memory-management functions manage system memory. There are two categories of functions: those that manage global memory and those that manage local memory. Global memory is all memory in the system that has not been allocated by an application or reserved by the system. Local memory is the memory within a Windows application's data segment. The following list briefly describes each memory-management function:
| Function | Description | |
| DefineHandleTable | Creates a private handle table in an application's default data segment. | |
| GetFreeSpace | Retrieves the number of bytes available in the global heap. | |
| GetWinFlags | Retrieves information about the system memory configuration. | |
| GlobalAlloc | Allocates memory from the global heap. | |
| GlobalCompact | Compacts global memory to generate free bytes. | |
| GlobalDiscard | Discards a global memory block if the lock count is zero, but does not invalidate the handle of the memory block. | |
| GlobalDosAlloc | Allocates global memory that can be accessed by DOS running in real or protected mode. | |
| GlobalDosFree | Frees global memory previously allocated by the GlobalDosAlloc function. | |
| GlobalFlags | Returns the flags and lock count of a global memory block. | |
| GlobalFree | Removes a global memory block and invalidates the handle of the memory block. | |
| GlobalHandle | Retrieves the handle of a global memory object. | |
| GlobalLock | Retrieves a pointer to a global memory block specified by a handle. Except for nondiscardable objects in protected (standard or 386 enhanced) mode, the block is locked into memory at the given address and its lock count is increased by one. | |
| GlobalLRUNewest | Moves a global memory object to the newest least-recently-used (LRU) position. | |
| GlobalLRUOldest | Moves a global memory object to the oldest least-recently-used (LRU) position. | |
| GlobalNotify | Installs a notification procedure for the current task. | |
| GlobalReAlloc | Reallocates a global memory block. | |
| GlobalSize | Returns the size (in bytes) of a global memory block. | |
| Function | Description | |
| GlobalUnlock | Invalidates the pointer to a global memory block previously retrieved by the GlobalLock function. In real mode, or if the block is discardable, GlobalUnlock decreases the block's lock count by one. |
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| GlobalUnwire | Decreases the lock count set by the GlobalWire function, and unlocks the memory block if the count is zero. | |
| GlobalWire | Moves an object to low memory and increases the lock count. | |
| LimitEMSPages | Limits the amount of expanded memory that Windows will assign to an application. | |
| LocalAlloc | Allocates memory from the local heap. | |
| LocalCompact | Compacts local memory. | |
| LocalDiscard | Discards a local memory block if the lock count is zero, but does not invalidate the handle of the memory block. | |
| LocalFlags | Returns the memory type of a local memory block. | |
| LocalFree | Frees a local memory block from memory if the lock count is zero and invalidates the handle of the memory block. | |
| LocalHandle | Retrieves the handle of a local memory object. | |
| LocalInit | Initializes a local heap in the specified segment. | |
| LocalLock | Locks a block of local memory by increasing its lock count. | |
| LocalReAlloc | Reallocates a local memory block. | |
| LocalShrink | Shrinks the local heap. | |
| LocalSize | Returns the size (in bytes) of a local memory block. | |
| LocalUnlock | Unlocks a local memory block. | |
| LockData | Locks the current data segment in memory. | |
| LockSegment | Locks a specified data segment in memory. | |
| SetSwapAreaSize | Increases the amount of memory that an application reserves for code segments. | |
| Function | Description | |
| SwitchStackBack | Returns the stack of the current task to the task's data segment after it had been previously redirected by the SwitchTasksBack function. | |
| SwitchStackTo | Changes the stack of the current task to the specified data segment, such as the data segment of a dynamic-link library (DLL). | |
| UnlockData | Unlocks the current data segment. | |
| UnLockSegment | Unlocks a specified data segment. |