Disk usage on Windows 10 reaches 100% causing the computer to freeze

The important clue is that an SSD-health check can be normal while Windows still reports 100% active time and freezes. That percentage describes how busy the storage path is, not only whether the drive has failed. Press Ctrl+Shift+Esc, select the Processes tab, and sort by Disk while the problem occurs; then use the Performance tab to see whether the busy disk is the system drive. Note the process name, transfer rate, and available free space. Windows Update, antivirus scanning, indexing, a game launcher, or a storage-driver issue can create bursts, but repeated freezes need evidence. Install pending Windows updates and current chipset, storage-controller, and SSD firmware from the PC or drive maker. Disconnect optional external storage and retry. If a single process consistently drives the activity, troubleshoot that application; if System dominates, save the event details and test with a clean boot before disabling services randomly.