Right-click inside the drive and choose Paste. ... A fresh installation of Windows 10 typically requires around 20–25 GB of space. Microsoft Community Hub How to Compress C Drive on Windows 11 / 10

If you’ve decided to move forward, follow these steps to enable compression:

Furthermore, the risk profile of compressing the C: drive is uniquely high compared to compressing a secondary data drive. The C: drive houses the operating system, critical system files, hibernation data, and virtual memory. Compressing system-critical files can, in rare cases, lead to instability. A more pressing technical limitation involves the hibernation file ( hiberfil.sys ) and the page file ( pagefile.sys ). If the drive is compressed, these files may fail to expand or contract as needed, potentially leading to system crashes or "blue screens of death" (BSOD) during sleep or wake cycles. Additionally, on SSDs, the increased frequency of writing and rewriting compressed data can theoretically contribute to "write amplification," slightly reducing the drive's lifespan, though this is a minor concern compared to the performance impact.

How to Safely Compress Your C: Drive to Reclaim Disk Space Running out of space on your primary hard drive is one of the most common—and frustrating—PC issues. When your C: drive hits the "red bar" in File Explorer, your system slows down, updates fail to install, and apps may crash.

Press Windows Key + E and go to This PC .

You don’t need to download sketchy third-party "cleaner" software; it’s a native Windows feature.