@programin – some hosting sites allow you edit/create web pages through an editor provided by the hosting company. and they will also let you upload images and other files through an interface on the control panel of the site in which your site is hosted. all of this without having to install anything on your computer. although, I wouldn’t suggest using the host’s html editor and uploading interface, just because you’ll spend more time uploading stuff than necessary since you can only upload so much at a time.
if you need a free HTML/WYSIWYG editor for windows, try NVU or Kompozer.
and as mentioned before, FileZilla is a great FTP client for uploading. If you need further help in uploading to your site, you should be able to find that kind of info in the help files for the hosting company.