Hi, I am new to the forum and hope that someone can help me with a problem I have been having lately. It is identical or related to the problem described here:forums.mydigitallife.net/threads/1910-DfrgNtfs.exe-in-Vista-SP1 Sporadically, the process with the name DfrgNtfs.exe will start. Usually it goes through about 2 cycles (PID changes but name remains the same). It is NOT the weekly defragmenting process. My schedule is set to Wednesdays 1 am and this will go about every Wednesday without a problem. Deactivating the scheduled scan does not affect the automatic start of DfrgNtfs.exe as part of Boot optimization. About two days ago I experienced the following: the process would start automatically and would not stop again. As soon as one Process DfrgNtfs.exe with a specific PID finished, another one (different PID) started. This went on for about 3 hours. Here is what I noticed: In the regular (wednesday) defragmentation process both HDD activity ensues all the time and the process itself doesnt take so much CPU. The automatic process (probably boot opt.) locks up at 50% CPU (one full core of my Dual Core) drops to 0% and then rises again to 50% as a new PID is introduced. HDD activity happens only at the time that the process itself is to 0%. My questions now are: I never had a problem with the automatic defrag process as part of boot optimization until a few days ago. What should I do? Really deactivate it via Registry tweaks? Or should I still wait and see? Why are the two types of defragmentation so different (continous HDD activity vs. lock-up of CPU). Is this not the same activity of defragmenting? Do you think it is normal that the automatic. process would not stop for several hours until I interrupted the process through moving my mouse? I would really appreciate your help because Im very concerned about what happed and what I should do. Thanx in advance!