why does hard drive continue to run all the time

[Aramax]

I have Installed Windows Vista on my computer again and installed the softwares that i use the most. I have not installed any junk application and kept my computer as clean as possible. But i think something is still wrong goin on with my system. My hard disk keeps spining all the time even if i am doing nothing on my computer. Is something wrong?

[Maxforu]

This may happen because Vista might be running the indexing service which makes searching of files, data and commands easily... Also Vista runs the defragmentation when user is idle and not using the computer at all, this is too speed up the computer and better user experience... Though Vista has many great features, still it failed to cast a spell on users...!!

[Rawko]

May be you have a antivirus program running in the background when you noticed the hard disk running when you were idle. And yes, Vista does, disk defragment when the computer is idle and backs off when a user does any operation. Also Vista moves files from one location to other just to keep the disk from sleeping more frequently. Vista takes the most used files into memory for faster access...