Antivirus without updating
Builds of Windows 10–like the fall update, Windows 10’s first big update–aren’t like normal Windows updates or service packs at all.
Instead, they’re more like upgrading to an entirely new version of Windows.
As part of the upgrade process, Windows leaves your old Windows installation–or old Windows build–files in the “Windows.old” directory on your system drive. This is also displayed as “Previous Windows installation(s)” in the Disk Cleanup application.
Windows may remove programs during an update for compatibility reasons.
Otherwise, assuming it’s been less than 30 days, your old program files will still be there for you to recover.
To find them, open File Explorer and navigate to the , depending on where Windows stores the data.
This is the takeaway from some people’s experiences with the “November update,” Windows 10’s first big update.
However, if you’ve removed old Windows installations using Disk Cleanup or manually deleted the folder after the upgrade, it won’t be there.Here’s what’s going on, and what you can do about it.To start: Windows won’t just remove programs at random times.If a program is known to cause crashes, bugs, or otherwise conflict with Windows, Windows may remove it to keep your system stable.If this happens, the “All of your files are exactly where you left them” screen will appear like normal–this screen always appears during major updates–but Windows will actually have removed some of your program files.
If you run into this problem and you want to get the program back, just reinstall it.