Hi bambibear,
This ubuntu is optional, and does not
have to be done. It is merely another good tool to have to prepare for the worst, should it ever happen again.
1.)
Yes, when you download Ubuntu it will be saved on your hard drive, most likely in your Downloads folder.Using the links provided, you will be downloading an .iso file. Either 32-bit or 64-bit Ubuntu should work for you.
An .iso file is similar to, but different than, all files on your computer. It is a compressed file, and must be opened (expanded) to utilize the many files within it. Ubuntu is downloaded as .iso because, when it is expanded onto a hard drive, it will take up more than 2 GB (Gigabytes) of space. Obviously, compressing the many files that comprise Ubuntu will save time downloading, and also allows the core of the operating system to be placed on a CD-ROM (700 MB).
Latest version of Ubuntu download comes to 701 MB, .iso.
So, merely copying the .iso file to a cd will not work. You must use a program such as Roxio or Nero, or Imageburn to open the .iso file and then burn it to a cd.
2.)
So, it is at this point, you would put the cd in the cd drive. You then point your Roxio, Nero, or Imgburn program at the .iso file, (double-click? the file)
and then the burning process will start.It is when you burn the .iso file is when you open it and make it bootable. If done properly, (to check for proper burning) when you open the cd to view the contents inside, you will see several folders. If no folders are present, then you have not burned the .iso file, but only copied it to the cd.
Imgburn is a free image burning program, essexboy and jeffce have had users use this program from time to time to burn programs needed to clean infected systems. Personally, I use a vendor paid program, as I find the need to run Nero to burn .iso files more frequently than not.
If only using a burning program infrequently, then Imgburn will suffice.
http://www.imgburn.com/ Use the latest version, ImgBurn v2.5.7.0, and this should work for you.
You can always uninstall Imgburn when done and get another copy if you need it later.
To clarify, Ubuntu is a different and separate operating system from Windows 7. Windows 7 cannot see Ubuntu, but Ubuntu can see Windows 7, and that difference is useful when 7 will not start. You will be able to perform the same copy/paste functions within Ubuntu as you can in 7, and thus save any files you wish to keep should 7 ever fail to start.
As long as you never install Ubuntu on your hard drive, run only as 'Live CD' (Try Ubuntu without installing) you will be fine.
What running Ubuntu as a Live CD means is, the entire operating system is running in system memory only (Ubuntu, that is), no part of Ubuntu is ever installed onto your hard drive
(unless you tell it to). Running in memory means that Ubuntu will disappear completely (poof!) when you restart your system after you are done with your session in Ubuntu Live CD, and Windows 7 will never know. Windows 7 will not be affected as long as you do not install Ubuntu.
Ubuntu is just a very useful tool when disaster strikes, is all.
Follow the above steps, and all should work out.