Unknown application accesses the Hard Drive

I recently rebuilt this PC and reinstalled windows on it and a new interesting problem has cropped up. Something is accessing the hard drive and I can’t figure out what it is.

When the PC is idle and nothing is running I can hear the HD being accessed and the HD light flashes. This is not a huge issue but I’ve never had a PC do this before and I’d rather not shorten the life of the HD because something is doing something that it shouldn’t be.

I have windows indexing turned off. It does it when the Anti virus is running and when its not. System restore is also off. I’ve disabled just about everything I can find that does not need to be running and it is still doing it. Its almost as though there is some windows service that is accessing the hard drive and doing something.

Its not like its writing a lot of data but you can hear it every few seconds doing something. Does anyone know of a way I can figure out what is accessing the hard drive so I can disable it? I have several other PCs here and none of them have this problem.

Also the writes are not in any particular pattern. Its just random reads / writes or something. Anyone have any thoughts on this?

Do you have your page file set to dynamic or to a fixed size?


(Mark Russinovich who 0wn!d Sony)


Are you using Vista? If so, then it’s probably the OS doing a bunch of file flagging as part of its prefetch maintenance. I wondered about it myself until I used the Filemon tool wisefool linked to.

I’ve had this happen with svchost.exe using up almost 100% CPU resources at times, causing the hard drive access light to stay on for a while until it settles back down to 0% usage. It’s a well-known issue.

I had the same issue for the reasons Kareem mentioned. It was kinda spooky when it first happened…

Usually when this happens to me, it’s the system making a restore point.

That’s when I remember to turn off sytem restore…

I just had a situation where my PC kept rebooting while Vista was loading, and system restore fixed it. So, you might think twice about disabling it, since under Vista it actually seems to work. :)