Are you one of the people who upgraded their computer from their old Windows to Windows 10? It probably disappeared into the mists of Windows past, right?
Your old operating system didn’t erase, rather it only remain in a folder called Windows.old. Depending on the size of that old version, it could be taking loads of space.
First things first: If you think you might want to downgrade from Windows 10 back to the previous version, don’t delete that folder.
Second, unless you’re seriously strapped for space on your hard drive, you don’t have to do anything: Windows 10 will automatically delete the Windows.old folder one month after you performed your upgrade.
If you would like to reclaim that storage now, you can delete the folder immediately though not in the way you might expect. Indeed, if you simply click the folder and then press the Delete key, Windows will tell you you need permission and some other things.
Below is how to delete the Windows.old folder:
Step 1: Click in Windows’ search field, type Cleanup, then click Disk Cleanup.
Step 2: Click the “Clean up system files” button.
Step 3: Wait while Windows scans for files, then scroll down the list until you see “Previous Windows installation(s).”
Step 4: Check the box next to the entry, then make sure there are no other boxes checked (unless you do indeed want to delete those items). Click OK to start the cleanup. You are done!