That's not a memory leak. That's windows' disk cache being stupid. A memory leak would be visible in task manager under the process that is leaking. In the case of uTorrent, the INSTANT the process exceeded 2GB of ram, it would crash. thx for the explaination is there any solution to the problem...? I remembered 3.2.x stable didn't cause it, but seems 3.2.x has a very bad DISK I/O for me (when I use 3.2.x, it always takes >15min to shutdown my PC after quit UT...but 3.3 is normal)