I am having my website made on iis 7.5 server. I want to add a blog like - mysite.com/blog. I don’t want to change any thing in my existing website mysite.com just want to have a wordpress blog in subdirectory. What should I do for this?
I have read somewhere that I have to create a folder in my root directory and then I have to install wordpress there. Is this the only thing I will need to do? Also, can I create a subfolder via FTP.
Yes, use ftp to create the new folder and drop the unzipped wordpress files into it.
Then run the Wordpress Install script making sure you have set up the database before it.
Why do you have the address of a condo in Renton as your location when you are in an entirely different country?!
Go to the C-Panel then choose file system…After that go to the html directory…there you can install wordpress but before that you must create database for it 
Make sure PHP is enabled and running on the IIS server. You will also need MySQL to be installed. It is very easy to install both of these in an insecure manner so maybe get a professional to do it for you.
You can then simply upload wordpress to a sub-folder on your site and run the Wordpress set-up link.