When you get to screen in the recovery process that asks you to select a language, is there not a drop down arrow at the right hand end of the box listing the default language ? If you click on this you should get a list of all available languages. You should be able to scroll down this list to choose the language you want.
If you use the recovery option on this computer you will re-install Win 7 Starter. If you wish to use the Win 7 HP disc you possess then the installation will automatically format your hard drive as part of the install process. You need to be aware that both processes will wipe out your existing data, so this needs to be backed up first.
The complicating factor is that you say your computer is badly infected and the last thing you want to do is to reload any of these infections when you reinstate your data. To get around this, I suggest you use either empty memory sticks or an external drive but get it or them scanned on a known clean computer to verify they are empty and clean. Then back up your data, then scan your data on these drive(s), again on a known clean computer, before you re-install your data.