Thanks for the fast reply. Yes excatly, I need to prevent the user from even viewing this particular sheet, but I want it to stay in there since it contains a bunch of codes. I saw I can maybe hide it, but is it possible that when the user click on it, it asks for a password or just refuse access until the document is unprotected?Yes, you can protect (lock) individual sheets, and optionally use a password. However, what do you want to prevent? Protecting a sheet will still allow a user to view it, but they can't change any locked cells. If you want to prevent a user from even viewing it you have to take further steps.
Thanks for the tip! So execpt for hidding the tab there’s no way to just “lock” the access with a password? Not even with VBA code?Hide the sheets you want to hide
Go to Review, Protect Workbook, check "Protect structure"
Provide a password
Click OK
Make sure you do not forget this password!
Users will not be able to unhide the worksheet without the password. They will also not be able to hide, rename, add, or delete worksheets.