How do I create a secure folder to use online

I want to create a pw protected folder where I can put sensitive information and have it stored in my gmail account. That way I can access it anywhere with just the pw. I tried using a program called KeepPass but you have to have that program on your pc to open it. I looked at creating a batch file from online help sites but that doesn't seem secure.
What are the option without buying some software . I only want to create one file to protect.

Thanks

it could be either. Here is what I was hoping to do. I have a file with all my sensitive passwords on it. I want a way I can store it in my gmail account so when I am away on a trip using a unfamiliar pc, I could go to my gmail open the file or folder with a password and read the content, without having to install some third party software.

Thanks

You can write down your PWs in an Excel sheet and set a PW to it and then you can open it by using Google document. In this way you have it locked and is always accessible.

LastPass allows you to open a file online without the software installed on your PC? I do have the 7 Zip file already created but I am concerned that I may be on a pc that won't allow any installations of software even a portable version.
The idea (excel sheet)has merit as long as google doc does open an excel sheet. What the procedure for pw protecting a excel sheeet?

Thanks again for all the advice

To set a pw in an Excel document look at this page: How to password protect a excel 2010 worksheet

You can use the same procedure to change the pw again.