Bytesweep Find out what is filling your C: drive
Windows Storage settings give you a pie chart and vague categories. Bytesweep maps every folder and file, then removes the specific things that eat a Windows disk.
14-day free trial, no card needed. Then $15 once for 3 computers. No subscription. Runs offline.
The usual Windows space thieves
Windows.old after a feature update (often 20 GB or more), the SoftwareDistribution update cache, the WinSxS component store, hiberfil.sys at roughly 40% of your RAM, Delivery Optimization files, System Restore shadow copies, thumbnail caches, and WSL or Docker Desktop ext4.vhdx disks that only ever grow.
Tools that need a command, not a delete
Some of that cannot be freed by deleting files in Explorer. Bytesweep runs the right operation for each: DISM component cleanup, powercfg to remove the hibernation file, vssadmin to shrink restore points, and Optimize-VHD or diskpart to compact WSL and Docker virtual disks. Admin actions use the standard Windows elevation prompt.
Right-click any folder
The installer adds "Scan with Bytesweep" to the Explorer context menu, so you can measure a folder the moment you wonder about it.
Bytesweep vs CCleaner, WinDirStat, WizTree and TreeSize
| Bytesweep | CCleaner | WinDirStat | WizTree | TreeSize Personal | |
|---|---|---|---|---|---|
| Price | $15 once | Free tier, paid yearly | Free | Free personal | €20.40/user/year |
| Payment model | One-time | Subscription | Open source | Free / commercial licence | Subscription |
| Visual views | 8 | 0 | 1 treemap | 1 treemap | 1 treemap |
| Cleans junk automatically | Yes | Yes | No | No | No |
| Windows.old & WinSxS cleanup | Yes | Partly | No | No | No |
| Compact WSL / Docker vhdx | Yes | No | No | No | No |
| Duplicate + similar photo finder | Yes | Duplicates only | No | Duplicates only | Duplicates only |
| One-click undo | Yes | No | No | No | No |
| Mac & Linux too | Yes | Mac only | No | No | No |
Questions
Is it safe to delete Windows.old?
Yes, once you are sure you will not roll back to the previous Windows version. Bytesweep takes ownership and removes it properly, which Explorer cannot do.
What is hiberfil.sys and can I remove it?
It is the file Windows writes memory into when hibernating, sized at roughly 40% of your RAM. Turning hibernation off deletes it. Sleep still works, but Fast Startup is disabled.
Does it work on Windows 10?
Yes, on Windows 10 and 11, 64-bit.
Or start the free 14-day trial first. Related: Mac, Windows, Linux, duplicates.