When Windows detects that the user has been inactive for a certain time period, it will execute certain optimisation tasks whilst there is plenty of spare processing power available. One of these tasks is to create a background process that will defragment and optimise hard disk drives. Depending on the drive partition type, Windows will spawn either dfrgntfs or dfrgfat to handle the optimisation.

I've decided to disable this process for Windows under my OS X Parallels bootcamp installation. Every now and then I'll hear the hard drive spinning up and have a fair chunk of CPU get eaten away as the hard drive defragmentation process runs. It's a real pain when I'm in the middle of coding, web browsing or anything else. So I've decided to disable the optimisation process altogether, as I don't really care about my bootcamp install all that much. If it starts running really, really slowly, I'm happy to reinstall Windows.

How to disable drive optimisation:

1. Head over to the Microsoft Power Toys to download and install Tweak UI

2. Fire up Tweak UI and select the 'General' tree item from list of options

3. Uncheck 'Optimize hard disk when idle'

4. Apply the settings