Online vs. Offline defragmentation

O&O Defrag V6 can carry out defragmentation runs online and offline. In this context, ôonlineö means that the defragmentation is carried out in the background whilst your system is running. Thus, you can carry on your work as usual. However, some system files are locked by the operating system whilst it is running, and these files can only be defragmented before the operating system has locked them. This is possible in the so-called start phase of Windows. This is before the usual operating system processes take place and you as user cannot start any applications. Defragmentation at this time is known as offline defragmentation (or often Boot-time defragmentation).

The following table shows which file types can be defragmented on- and offline, according to which operating system you are running. If online defragmentation is impossible, O&O Defrag will automatically select offline defragmentation. This will take place at the next system start. You can stop this at any time by pressing any key.