"I went for an interview last week and saw the interviewer with my resume. I was surprised to see that it did not resemble what I sent out. I sent my resume by email. How can I prevent that from happening?"
When you email your resume and the person at the receiving end has a different word processing software, that can lead to formatting inconsistencies, a thing to avoid, if possible. Further, even when you both have the same software, you might have different versions of that software (i.e. one person might have a more recent version), which could also lead to difficulties. A good way to avoid this is to send your job applications in “.pdf” format. Most companies pdf their documents for external communications nowadays and will have no problem opening the documents that you send them.
The following websites offer free pdf converters: