Regarding your licence, you can install/reinstall on the same PC as many times as you like; the '2' licences refers to how many computers you can install on (typically one laptop plus either another laptop or a desktop).
Regarding the missing file, how did you uninstall Outlook?
You can download a backup copy from
http://office.microsoft.com/en-us/pr...101853122.aspx, but you won't get any files that aren't on the installation disk you already have.