How to remove the hard drive’s red bar alert in Windows 10?

You can’t change the percentage because it’s hardcoded.

Run regedit.exe as administrator

Open HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Drive

Change the values for both TileInfo and PreviewDetails keys by removing the phrase “System.PercentFull;” (without the quotes)

TileInfo key before and after

prop:*System.PercentFull;System.Computer.DecoratedFreeSpace;System.Volume.FileSystem
prop:*System.Computer.DecoratedFreeSpace;System.Volume.FileSystem

PreviewDetails key before and after

prop:*System.PercentFull;System.FreeSpace;System.Capacity;System.Volume.FileSystem;*System.Volume.BitLockerProtection
prop:*System.FreeSpace;System.Capacity;System.Volume.FileSystem;*System.Volume.BitLockerProtection

And restart Windows. You should be able to see the absence of the color bars !