Mary, your easiest step would be to download PAF 5 from http://www.familysearch.orghttp://www.familysearch.org and use that to read your uncle's file. First, however, you have to determine the type of file he sent to you. Is it a GEDCOM file, a copy of his data, or a backup file? If the file has an extension of ".ged" it is a GEDCOM. If the extension is ".bak" it is a backup file. And if it has a ".paf" extension it is a copy of his data.
After you have installed PAF 5, it will look for any data you may have. So if your uncle's file is a ".paf" file it will locate it and you will be asked if you wish to convert it (to PAF5). If it is a GEDCOM file, you can click on FILE|IMPORT and import it to PAF5. If it is a backup file, you will need to create a new database in PAF 5 of the same name as your uncle's file, then click FILE|RESTORE.
PAF 5 is FREE from Family Search. You will find it is an excellent program, user friendly and many features. You probably will not want to go back to FTM after using it :-)