How can I make names appear on Messages and not numbers?

Question

When I use Messages, instead of my conatcts's names all I get is their numbers. I have a second laptop (MacBook Air) and there I get the names correctly. I checked the configuration in Preferences to make sure it's the same. Still I can't figure it out. Anybody please?
Thanks,

Answer 1

To what page does the home page get changed?
You can do a malware check with several malware scanning programs on the Windows computer.<br>
Please scan with all programs because each program detects different malware.<br>
All these programs have free versions.
Make sure that you update each program to get the latest version of their databases before doing a scan.
*Malwarebytes' Anti-Malware:<br>http://www.malwarebytes.org/mbam.php
*AdwCleaner:<br>http://www.bleepingcomputer.com/download/adwcleaner/<br>http://www.softpedia.com/get/Antivirus/Removal-Tools/AdwCleaner.shtml
*SuperAntispyware:<br>http://www.superantispyware.com/
*Microsoft Safety Scanner:<br>http://www.microsoft.com/security/scanner/en-us/default.aspx
*Windows Defender:<br>http://windows.microsoft.com/en-us/windows/using-defender
*Spybot Search & Destroy:<br>http://www.safer-networking.org/en/index.html
*Kasperky Free Security Scan:<br>http://www.kaspersky.com/security-scan
You can also do a check for a rootkit infection with TDSSKiller.
*Anti-rootkit utility TDSSKiller:<br>http://support.kaspersky.com/5350?el=88446
See also:
*"Spyware on Windows": http://kb.mozillazine.org/Popups_not_blocked