Hi,
some info :
- your system is: NAV 2009R2 for SQL server or for Native database ?
- is a new NAV installation on old existing server ?
- are you using SQL users or DOMAIN users ?
- NAV client installed on server run fast or slow with enabled network connection ? test to connect using 'local' or '.' instead of sql server name
some checks:
> check installed release & existing permissions on xp_ndo.dll for xp_ndo_enumusergroups & xp_ndo_enumusersids
> check that.NET 3.51 SP1 or .NET 4.0 is installaed
> check that ALL NAV prerequisites are installed on Nav server & on Nav clients
> if you don't need RTC disable use NAV Server flag
> use standard security insted of enanched if you don't need to manage sql server data slice permissions
> try to connect with Named Pipes insteaf of TCP