I see, I was not understanding your problem correctly. It looks like Word has chosen a foreign language character set for a portion of your text. I'm not sure how to fix this or if it can be fixed. However, my first guess would be to play with the language settings.

I would open the document, and press CTRL+A to make sure all text is selected. I would then go to Review from the ribbon menu and click Set Language. Make sure all text is set to English. Try toggling the language detect feature.

I would also try to make sure that it's not something simple like a font change in the middle of the paragraph.

I wonder if the file is not damaged. Make a copy of the document
before you try the steps mentioned in the Microsoft KB document:

Click on this link to access it:

http://support.microsoft.com/kb/918429/en-us

Since you said that you are new to computers, you can try these steps
mentioned in the KB article:

Method 5: Force Word to try to repair a file
Step 1: Repair document
1. Click the Microsoft Office Button, and then click Open.
2. In the Open dialog box, click your Word 2007 document.
3. Click the arrow on the Open button, and then click Open and Repair.
Step 2: Verify that repairing the document fixes the problem
Verify that the strange behavior no longer occurs. If the strange behavior
persists, restart Windows, and then go to method 6.