smnirosh
I installed win7 to one hard disk. With a different computer name. It can join and loggin with user name. What can i do now.
Well that proves that a clean install of Windows 7 does connect to your SME server network OK, & login as a DOMAIN user.
So that also rules out any (serious) problems with SME server.
Clearly your issue is with the original Windows 7 installation.
Possibilities are corrupt files, missing registry entries, inappropriate registry entries, clashes with other installed programs etc (incompatibilities).
You really need to now troubleshoot the old Windows 7 install if you wish to retrieve or save installed software etc.
I think you are on your own to do that, this is a SME server forum, not a Windows troubleshooting forum.
I agree with Stefano that it sounds like you do not know what you are doing, yet you also sound like you are playing at fairly serious networking setups etc, your knowledge & abilities as compared to what you are doing, does confuse me.
Best you engage the services of someone who understands Windows & Windows networking to NT style domains very well & maybe they can return your old Windows setup to more standard settings that work OK with SME server.
What went wrong along the way, I do not know.
I think only you can tell us, but so far you are not really telling what caused all this.
There seems to be very poor administrative record keeping regarding that Windows 7 workstation/server, so the organisation &/or its staff is at fault.
Where is the last known good working backup of the Windows 7 computer ?
What, no backup !