WINDOWS SERVICE
defragsvc: Optimize drives
Helps the computer run more efficiently by optimizing files on storage drives.
TECHNICAL SUMMARY
| Service name | defragsvc |
|---|---|
| Display name | Optimize drives |
| Runs from | C:\Windows\System32\svchost.exe |
| Command line | svchost.exe -k defragsvc |
| Runs as | LocalSystem |
| Verdict | Leave it alone |
| Microsoft, Windows Server 2016 guidance | No guidance |
Paths, signer and service account observed on Windows 11 build 26300 on 12 November 2026. Run the commands below to check your own PC.
Should you touch it?
Leave it aloneIts default startup type is Manual, and on the PC used for this page it was stopped: it is not a permanent cost. Microsoft's guidance rates it OK to disable on fixed-purpose devices, but on a PC it is the service behind drive optimization, which Microsoft documents as including retrim on SSDs.
What PC Tweaker does with it
PC Tweaker does not change this service. No control in the catalogue stops it, disables it or edits its start type.
Check it yourself
See its state and start type
PowerShellGet-Service defragsvc | Format-List Name, DisplayName, Status, StartType sc qc defragsvc
Common questions
What does the defragsvc service do?
Helps the computer run more efficiently by optimizing files on storage drives. It runs C:\Windows\System32\svchost.exe (svchost.exe -k defragsvc) as LocalSystem.
Can I disable defragsvc?
Leave it alone. Its default startup type is Manual, and on the PC used for this page it was stopped: it is not a permanent cost. Microsoft's guidance rates it OK to disable on fixed-purpose devices, but on a PC it is the service behind drive optimization, which Microsoft documents as including retrim on SSDs.
defragsvc is causing high disk usage. Is that normal?
While an optimization runs, yes. Microsoft documents that defragmentation runs as a scheduled maintenance task, typically every week. On Windows 11 build 26300 that task is \Microsoft\Windows\Defrag\ScheduledDefrag, which runs defrag.exe -c -h -o -$.
Does it defragment an SSD?
Microsoft documents a separate policy for SSDs when the scheduled task runs: traditional optimization, which includes defragmentation and retrim, is done once per month, and changing the task's frequency does not affect that monthly cadence. The Optimize Drives app shows each drive's last run.
How do I check that it is the real service?
On build 26300 it is registered as svchost.exe -k defragsvc, runs as LocalSystem and loads C:\Windows\System32\defragsvc.dll, signed by Microsoft Windows. It depends on RpcSs.