Hi Vito, you can use reimage to remove any infections on your computer. According to the extension of your encrypted files we can assume that your computer was infected by either TeslaCrypt ransomware (in this case download a free remover - http://download.bleepingcomputer.com/BloodDolly/TeslaDecoder.zip) or Alpha Crypt ransomware (no decrypter available). To be sure what ransomware infected your server you can use this service https://id-ransomware.malwarehunterteam.com/