I'm in the process of installing Windows 10 on my Macbook Pro (macOS 10.13.4/17E202, 256 GB of storage, no partition), but Boot Camp says I need at least 40 GB of storage.

So I freed up some space by removing some files, and "About My Mac" now shows almost 100 GB of free space on my Mac:

[![enter image description here](https://i.stack.imgur.com/WoZ3g.jpg)](https://i.stack.imgur.com/WoZ3g.jpg)

However, the Disk Utility shows only 33 GB of free storage... 3 times less:

[![enter image description here](https://i.stack.imgur.com/rK4VI.jpg)](https://i.stack.imgur.com/rK4VI.jpg)

The trash is empty, and I restarted my computer twice. I also used Onyx utility to free up some more space, empty caches, etc. But there is still this huge difference.

I tried to find "hidden files", that could cause this difference, using the Disk Inventory X app, but it shows 100 GB of free storage...

Another strange thing that happened: after I restart the computer, the status bar at the end of the finder shows 33 GB of free storage. But after 2-3 minutes, this number changes to about 100 GB... As if some cached values were used while the Mac is updating the folder sizes.

I'm pretty sure I have 100 GB of free storage, because I removed dozens of GB of photos and apps.

What's wrong? I'm kind of lost!