1 Is It Actually Corrupted?
First, let's rule out the common false alarms.
Before assuming the file is damaged, check these common causes of extraction failure that have nothing to do with corruption:
Wrong password. If the ZIP is encrypted and you're entering the wrong password, some tools will give a vague error instead of specifically saying "wrong password." Try the password again — copy and paste it to avoid typos.
Incompatible encryption. Older Windows versions can't open ZIPs with AES-256 encryption. Try opening with WinZip or 7-Zip instead.
File path too long. Windows has a 260-character path limit. If the ZIP contains deeply nested folders with long names, try extracting to C:\Temp instead.
Not enough disk space. The extracted files could be much larger than the ZIP itself. Check your available storage.
2 How to Verify If the File Is Damaged
Test before you attempt repairs.
Use 7-Zip's built-in test
Right-click the ZIP file → 7-Zip → "Test archive." This checks every file inside without extracting anything. If it reports errors, the file is genuinely corrupted.
Check the file size
Compare the file size to what the sender says it should be. If your copy is significantly smaller, the download was incomplete — you don't have the whole file.
3 How to Fix or Recover
In order of likelihood of success.
Re-download the file
This fixes the problem about 80% of the time. The most common cause of corruption is an incomplete or interrupted download. Delete your copy and download it again from the original source.
Try a different extraction tool
Different tools handle damaged archives differently. If 7-Zip fails, try WinZip. If WinZip fails, try 7-Zip. Sometimes one tool can extract files that another can't.
Use WinZip's built-in repair
WinZip includes a repair feature for damaged archives. Open WinZip → go to Tools or Settings and look for the repair/fix option.
Ask the sender to re-create and re-send
If nothing works, the file may have been corrupted before it was ever sent to you. Ask the sender to create a new ZIP and send it again — preferably via a file-sharing service (like Google Drive or Dropbox) rather than email attachment, since large files are more likely to get corrupted in email.