Myth: Windows reserves 20% of your internet bandwidth (and you can 'unlock' it) — via Jake Harfield, Help Desk Geek
MythNeeds adminWindows 11Windows 10
Tips telling you to set 'Limit reservable bandwidth' to 0% claim it frees up 20% of your connection. Bandwidth isn't held back. The 20% is only a ceiling on what apps that ask for QoS priority can reserve, and when nothing reserves it, every app can use it.
What to do instead
- Leave Computer Configuration → Administrative Templates → Network → QoS Packet Scheduler → Limit reservable bandwidth at Not configured.
- For slow internet, test with a cable instead of Wi-Fi, restart the router and check for background downloads (Settings → Windows Update → Advanced options → Delivery Optimization).
The myth dates back to Windows XP and still circulates in tweak guides. Microsoft describes the setting as a limit on the combined bandwidth reservations programs can make (80% of the connection by default), not as bandwidth taken away from everyone else.
Sources
- What is "Limit Reservable Bandwidth" in Windows and Why You Shouldn't Change It — by Jake Harfield, Help Desk Geek
- Policy CSP - ADMX_QOS: Limit reservable bandwidth (QosNonBestEffortLimit) — by Microsoft Learn
- Source reviewed
- 2026-11-02
- Link checked
- 2026-11-02
- Tested hands-on
- Not by Oddbyte.Me
Oddbyte.Me hasn't tried this on every Windows build, so keep the undo handy.