On modern laptops with soldered RAM and small SSDs, 25GB is a massive luxury tax to pay for Fast Startup.

By default, Windows 11 sets hiberfil.sys to approximately .

The hiberfil.sys file is a legitimate system file, and it's not a security risk. However, it's essential to keep your Windows 11 system and antivirus software up to date to prevent any potential security threats.

Using powercfg /h off reclaims the disk space but removes the ability to hibernate or use Fast Startup. Conclusion

Result: Your hiberfil.sys instantly drops to 20% of your RAM size (e.g., from 12GB to 3GB).

Hiberfil.sys is a system file in Windows that stores the contents of your computer's RAM (Random Access Memory) when you put your system into hibernation mode. When you hibernate your computer, Windows saves the current state of your system, including open applications, documents, and settings, to the hard drive. This allows your computer to resume where it left off when you restart it.