256
You can change password as many times you want. The password must be minimum 8 characters of length. It must contain numerals and characters too.
In common with most other computer applications you need to know what the password is before you can remove it. This is to prevent unauthorised alterations.Go to the Tool... Protection... Unprotect sheet menu and a dialog box will appear, in which you have to type the password.You can google 'Excel Password Unlocker' and it will give you many options.It wont give you your old password but make you change it so you can get in.
A strong password should be how many characters long?
255
8
Like all modern applications Excel has the capability to show things in various colours, so it can display characters in many colours.
255
16 characters - made up of a mixture of letters and numbers.
A cell can hold up to 32,767 characters, of which only 1024 can be seen in the cell.
You do not enter anything into a worksheet that is protected, unless the protection settings allow you to do so. You need to unprotect the sheet, insert the photo, then protect the sheet again. If the protection is locked with a password, then you need to contact the spreadsheet author to get the password. There are many ways to remove the password from an Excel workbook, but I will not discuss that topic here.
A range name in Excel can be up to 255 characters long. However, the name must begin with a letter, underscore (_), or backslash () and cannot include spaces or certain special characters. It's also important to ensure that the name is unique within the workbook.