A ZIP is a container for one or more files. Windows can let you look inside it much like a folder, which makes it easy to forget that you are still working with an archive. Extract a project into a normal working folder before making changes.

First, confirm where the ZIP came from and whether you expected it. Unpacking a file does not make its contents trustworthy. If an unexpected archive contains programs or scripts rather than the documents you were promised, stop and verify the source.

Create one clear working location

Right-click the ZIP in File Explorer and choose Extract All. Select a destination you can recognise, such as a new folder for the project. Review the destination before extracting, especially if a folder with the same name already exists. A fresh folder avoids confusing new contents with an older unpacked copy.

For a project containing linked images, spreadsheets or supporting files, extract the whole collection and retain its folder structure. Pulling out only the main file may separate it from material it expects to find beside it. Windows also supports dragging an individual file out of an archive when that is genuinely all you need.

Confirm where edits are saved

Open the document from the extracted folder, make a harmless test change and save it. Close the application and reopen that exact file to confirm the change survived. Check the application's recent-file location if two copies have similar names.

Keep the original ZIP until you have checked the extracted contents. It can help establish what originally arrived, but it does not automatically update when you edit an extracted document. If you need to provide a revised archive later, create it from the intended finished folder and inspect the resulting contents.

For an archive Windows cannot open, check its format and whether it is encrypted before concluding it is damaged. Use software appropriate to that format from its official source; do not install a random repair tool prompted by a download page.

Reference: Microsoft Support.