Copying Contacts from a backup

I recently had to reinstall Windows 10 from scratch.  I backed up my personal data.  I forgot to backup my contacts from Windows Live Mail.  After the new install was complete, I thought I would be able to copy my contacts into the WLM files and I would be good to go.  Unfortunately, I may have not put them in the correct location because I still do not see my contacts in WLM.  So I created a new contact in the app and went looking for that new contact to get the file location.  Can't find it.  Additionally, I noticed the backed up contacts have a file extension of "contacts".  I was going to try and import them through the import function in WLM but the file formats of "contacts" is not an option.  The standard formats are there but my backups have the "contacts' file format.  Would appreciate some help!