Hi there, Sorry for such a negative first post but I think I am encountering the issues mentioned in this thread. I have defraggler deployed on 450 workstations (XP SP2) on our network set to run a daily quick defrag. Yesterday I noticed one of the computers was going very slow, upon investigation I saw df.exe using 100% of the CPU and not appearing to do anything. When I then launched the GUI program and run a quick defrag, the same thing happens, the program builds the file list correctly, then once it starts defragging, CPU usage jumps to 100% in task manager and it is defragging only about 1 file every couple of seconds. I have tested with the newest defraggler version (1.18.185) and unfortunately the problem is still there. So far it is occuring on 2 out of the 7 computers I have tried. System restore is disabled on them all. Running a defrag in windows bult-in disk defragmenter works fine on them, they are new machines (2 years or newer) so I don't suspect any hardware failure. Aside from that negativity I am very pleased with the program and since rolling out across the network we have recieved no complaints at all, keep up the good work!