No. Definitely not! The absolute worst way to store your passwords is to store them on your computer in an unencrypted form. I recommend that you print the Excel file and then delete it. Then go into each site, starting with your sensitive sites (such as online banking), and change the passwords to a complex, unique password for each site, as I described in a previous answer. As I said, we go through passwords in detail in the course.
Q. I store my passwords in an Excel file on my computer, but you said that this is not good, right?