- By default, newer Windows set the defrag task to "Daily" but it automatically changes to "Weekly" the first time task scheduler runs silently in the backround. Windows wants to defrag as soon as possible on a clean install of the OS, then puts itself into weekly maintenance mode.
- You can't easily modify the defrag task due to its design in Windows, you can leave it as-is or disable the task with NTLite, but modifying it to a different frequency (monthly) is not easy. Even if you change the frequency, Windows will intentionally ignore you and defrag a drive once per month anyway, so the only good solution is to leave it default or disabled.
- If you have an SSD or similar, Windows will not actually run defragmenting on that drive weekly, even though it's scheduled. Instead, it runs features like retrim to make sure basic garbage collection is done.
- Windows does intentionally defrag an SSD once per month if the built-in volume shadow service (VSS) is enabled. VSS is disabled by default though on newer operating systems, so you would have to enable this file backup feature for the defrag to occur. Microsoft does this to prevent the backup program from having worse performance and taking too long. There is conflicting advice here, because this is what a developer says, but in the whitepapers it doesn't mention VSS and just indicates defrag will run once per month on an SSD.
- The developer states it is a misconception that fragmentation is not a problem on SSD. If an SSD gets too fragmented it can result in errors when trying to write/extend a file. Also, fragments mean more metadata to process while reading/writing a file, which reduces performance.
- The concerns about defrag wearing a drive down are grossly overblown too, it takes many cycles to wear out an SSD and it's just not possible for defrag to be an issue. That's not to say that there weren't all sorts of BIOS and firmware issues, driver problems, and Windows bugs that needed ironing out when SSD first launched, but the defrag concerns were bogus.