When you write a file to CD, Windows flips an invisible switch on the file that makes it “Read Only.” That’s because files on a CD can’t be changed: They’re permanently etched onto a plastic container, a handy way to keep them safely backed up and free of changes.

Unfortunately, when you copy that file back to your PC’s hard drive, Windows doesn’t automatically turn off that “Read Only” switch. And since the file is still marked as “Read Only,” Windows stops  you from saving any new changes or updates.

To turn off the “Read Only” switch yourself, follow these steps.

1. Right-click the Read Only file and select “Properties.”
2. Click to remove the check mark from the folder’s “Read-only” box.
3. Click OK, and Windows removes the file’s “Read Only” status.

Tip: To avoid this problem in the future, copy files into a Zip folder before copying them to your CD. (Right-click the files, choose Send To, and select Compressed Folder.) That way Windows only applies the “Read Only” setting to the Zip folder, but not its contents. When you unzip the folder, all its files will emerge without the Read Only setting.