In this video, I show you how to actually clean your C drive on Windows 10 or Windows 11 without using any external software. C drive is the most crucial drive on any PC, and when it starts filling up, your system performance can degrade fast—lag, slow loading, and overall sluggish behavior. So I walk you through a simple, practical cleanup routine using only built-in Windows tools. First, I delete temporary files the right way using Run (Win + R) with three commands: temp, %temp%, and prefetch. I select everything and use Shift + Delete to remove files directly, and if some files refuse to delete, I simply skip them. After that, I empty the Recycle Bin (this is not useless—this step genuinely frees space), uninstall unwanted programs from Settings > Apps > Apps & features, and then run Disk Cleanup from the C drive Properties menu to remove unnecessary system files. Finally, I also cover optimizing drives (mainly useful for HDD users) and I remind you to stop installing everything on the system drive by default—because that’s one of the biggest reasons C drive gets packed up in the first place.