Windows.old is a folder that contains archive information from previous windows system(XP/VISTA) when you upgrading to VISTA/Win7. It mainly stores programs and files that are required to run the earlier version of Windows and contains following folders.
- Windows
- "Documents and Settings"
- "Program Files"
You might end up having a windows.old folder taking up 20+ gigs on your system drive.
If you don’t need windows.old folder and want to safely delete this folder, follow the instructions below:
- Select Start, then All Programs, then Accessories, then System Tools, and then Disk Cleanup.
- If you are using Windows 7 or Windows 8, select Clean up system files. If you are using Windows Vista, select Files from all users on this computer.
- Select the Previous Windows installation(s) check box, and click OK.
IMPORTANT: Be sure to back up all important documents/files from the previous OS before following this article.