Whenever I install programs or games to my C: drive, where Windows 11 is installed, the whole computer becomes extremely sluggish. The mouse may stop responding, applications crash, and the system can effectively freeze until the operation finishes. The same thing happens while extracting archives, copying or moving files, and downloading through several game launchers or browsers, although Steam seems mostly unaffected. Task Manager shows the drive at 100% usage during these operations. What could be causing this, and is there a way to limit the disk activity or fix the underlying problem?
3 Answers
Make sure the C: drive has plenty of free space—ideally at least 10–15%, and more if possible. Windows needs working room for updates, paging, temporary files, and caching. A nearly full SSD can slow down dramatically during installations and large file operations, though severe freezing still makes checking the drive’s health important.
The 100% figure means the drive is fully busy, not necessarily that it is transferring data at its maximum speed. Check Task Manager for the process causing the activity, then check the SSD’s health and temperature. Limiting launcher download speeds may reduce the impact, but it won’t fix a failing or very slow system drive.
First check whether the SSD is actually healthy. Use a SMART monitoring tool such as CrystalDiskInfo and look at the health percentage, warnings, temperature, and error counts. An aging or failing drive can become saturated during writes and make Windows unresponsive. If the drive reports reduced health or errors, back up your important files and plan to replace it, preferably with a new NVMe SSD.

That may be the issue. The drive is a few years old and the health reading is around 54%, so I’m going to back everything up and look into replacing the NVMe drive.