Hello again.
I'm not real sure what you are asking in the first question, if you install in English the system will be English.
There is no upgrade path from Windows XP to Windows 7, it will have to be a clean install; the best way to go forward is to make back-ups of the data you need to save and do a wipe (secure erase) of the entire Hard Disk Drive, have a look at this information below.
All the installed programs/apps will have to be reinstalled so be sure to save the activation keys where applicable and be sure to post back with any further questions you may have and to keep us informed.