The VirtualAlloc API in Windows provides explicit control over commitment. You can reserve address space using the MEM_RESERVE flag, and commit with MEM_COMMIT. These can be combined into one.
Therefore, we cannot say that "Windows doesn't overcommit". Windows applications can overcommit. You don't know which ones might do that, for what purpose.
Therefore, we cannot say that "Windows doesn't overcommit". Windows applications can overcommit. You don't know which ones might do that, for what purpose.