People say they password protected an Excel file and mean two completely different things. One password encrypts the file so nobody can even open it. The other, Protect Sheet, only asks Excel to refuse edits. Both are called passwords, both are set in Excel, and trusting the second one to do the first one's job is how salary sheets leak.
The video in this series sets the strong one: the Password to open, through Save As, Tools, General Options. But every week someone protects a sheet on the Review tab, sees a password prompt, and walks away believing the file is secret. This guide puts the two locks side by side, states exactly what each one stops and what it does not, and tells you which lock, or which combination, fits which job.
This is the lock the video sets. It is applied to the file itself, before anyone opens it. Excel encrypts the workbook with AES, and without the password there is nothing to read: no values, no formulas, no sheet names, nothing. Programs other than Excel get the same scrambled bytes, so there is no side door through a different tool.
Use this lock when the question is who may see the data at all: payroll, ledgers, quotations, exam results, anything that becomes a problem if the file is forwarded, copied to a pen drive, or left in a shared folder.
Protect Sheet, on the Review tab, works inside an already open file. It tells Excel to refuse changes to locked cells: no typing over formulas, no deleting rows, no reformatting, depending on the options you tick. It was built for shared working files, where the danger is not a thief but a colleague with a heavy hand.
Here is the honest part. The protection is stored as a setting inside the file, and the data underneath it is completely unencrypted. Anyone who opens the file can read every value. And because the lock is a flag rather than encryption, on your own file it can be removed again; it was never designed to resist a determined person, and Microsoft does not sell it as security. Treat it as a seatbelt against accidents, not a safe.
The General Options dialog in the video contains one more box that confuses people: Password to modify. With it, the file opens read-only for everyone and the password is only needed to edit and save over the original. Nothing is encrypted, everything is readable, and any reader can save an editable copy with a new name.
It belongs to the same polite family as Protect Sheet. It protects your master copy from being overwritten by a helpful colleague, which is a real office problem, but it gives zero privacy. If you set this box by mistake while aiming for the open password, your file is far less protected than you think. The two boxes sit one above the other, so read the labels slowly.
Match the lock to the actual risk:
The prompts tell the truth if you read them. A password box that appears before anything of the file is visible is the open password, the encryption. A file that opens and shows a read-only message, letting you in when you choose Read Only, carries a modify password. A file that opens normally but shows an Unprotect Sheet button on the Review tab has sheet protection. Knowing which one you are facing tells you instantly whether you are dealing with real security or with an editing guard, and how serious a forgotten password would be.
The video sets this password on a real Excel file in about a minute, including the confirmation step and the save.
Watch Full VideoYes, easily. Sheet protection blocks editing through the Excel interface, but the file is not encrypted and every value in it can be read by anyone who opens it. For data that must stay secret, encrypt the file with a Password to open, the method shown in the video in this series.
It matters completely. A forgotten Password to open on a modern Excel file means the data is effectively gone, because the file is really encrypted and only guessing a weak password can help. A forgotten sheet protection password is a minor problem, because that lock is a stored setting on your own file, not encryption.
For a sensitive file that a small team edits together, yes. The open password keeps outsiders from reading anything, and sheet protection keeps insiders from breaking formulas while they work. Just record both passwords properly, because the open password has no recovery if it is lost.