Hi Mosheb,
If you are able to login with same user on different machine, it means that something is wrong with client user setting or may be AD account locked or expire so please check once again that you are able to loging other machine or not.
ClientUserSettings.config
<?xml version="1.0" encoding="utf-8"?>
<configuration>
<appSettings>
<add key="Server" value="apperp.c.com" />
<add key="ClientServicesPort" value="7046" />
<add key="ServerInstance" value="DynamicsNav70" />
<add key="ClientServicesProtectionLevel" value="EncryptAndSign" />
<add key="UrlHistory" value="apperp.chw.com:7046/DynamicsNav70" />
<add key="ClientServicesCompressionThreshold" value="64" />
<add key="ClientServicesChunkSize" value="28" />
<add key="MaxNoOfXMLRecordsToSend" value="5000" />
<add key="MaxImageSize" value="26214400" />
<add key="ClientServicesCredentialType" value="Windows" />
<add key="ACSUri" value="" />
<add key="AllowNtlm" value="true" />
<add key="ServicePrincipalNameRequired" value="False" />
<add key="ClientServicesCertificateValidationEnabled" value="true" />
<add key="DnsIdentity" value="" />
<add key="UnknownSpnHint" value="(net.tcp://apperp.c.com:7046/DynamicsNav70/Service)=Spn;(net.tcp://apperp.c.com:7046/dynamicsnav70/Service)=Spn;" />
</appSettings>
</configuration>
or you can copy from working machine this ClientUserSettings.config.